Changes

<xr id="tab:Overview_of_the_Most_Widely_Used_Silver_Grades"/><!--(Table 2.11 )--> shows the typically available quality grades of silver. In certain economic areas, i.e. China, there are additional grades with varying amounts of impurities available on the market. In powder form silver is used for a wide variety of silver based composite contact materials. Different manufacturing processes result in different grades of Ag powder as shown in <xr id="tab:Quality_Criteria_of_Differently_Manufactured_Silver_Powders"/><!--Table 2.12-->. additional Additional properties of silver powders and their usage are described in chapter [[ Precious Metal Powders and Preparations#Precious_Metal_Powders|Precious Metal Powders ]] und [[Precious_Metal_Powders_and_Preparations|Table Different Types of Silver Powders.]]<!--(Tab. 8.1.)--> Semi-finished silver materials can easily be warm or cold formed and can be clad to the usual base materials(<xr id="fig:Strain hardening of Ag bei cold working"/> and <xr id="fig:Softening of Ag after annealing after different degrees"/>). For attachment of silver to contact carriermaterials welding of wire or profile cut-offs and brazing are most widely applied. Besides these mechanical processes such as wire insertion (wire staking) and the riveting (staking) of solid or composite contact rivets are used in the manufacture of contact components.

currents < 2 A ''(<xr id="tab:Application Examples and Forms of Supply for Silver and Silver Alloys"/>)<!--(Table 2.16)''-->. Electroplated silver coatings are widely used to reduce the contact resistance and improve the brazing behavior of other contact materials and components.

<figtable id="tab:Overview_of_the_Most_Widely_Used_Silver_Grades"><caption>'''<!--Table 2.1211: Quality Criteria -->Overview of Differently Manufactured the Most Widely Used Silver PowdersGrades'''</caption><table class="twocolortable"><tr><th><p class="s12">Designation</p></th><th><p class="s12">Composition minimum Ag [wt%]</p></th><th><p class="s12">Impurities</p><p class="s12">[ppm]</p></th><th><p class="s12">Notes on Usage</p></th></tr><tr><td><p class="s12">Spectroscopically</p><p class="s12">Pure Ag</p></td><td><p class="s11">99.999</p></td><td><p class="s11">Cu &lt; 3</p><p class="s11">Zn &lt; 1</p><p class="s11">Si &lt; 1</p><p class="s11">Ca &lt; 2</p><p class="s11">Fe &lt; 1</p><p class="s11">Mg &lt; 1</p><p class="s11">Cd &lt; 1</p></td><td><p class="s12">Sheets, strips, rods, wires for electronic applications</p></td></tr><tr><td><p class="s12">High Purity Ag, oxygen-free</p></td><td><p class="s11">99.995</p></td><td><p class="s11">Cu &lt; 30</p><p class="s11">Zn &lt; 2</p><p class="s11">Si &lt; 5</p><p class="s11">Ca &lt; 10</p><p class="s11">Fe &lt; 3</p><p class="s11">Mg &lt; 5</p><p class="s11">Cd &lt; 3</p></td><td><p class="s12">Ingots, bars, granulate for alloying purposes</p><p class="s12"></p></td></tr></table></figtable>

Fig<figtable id="tab:Quality_Criteria_of_Differently_Manufactured_Silver_Powders"><caption>'''<!--Table 2. 12:-->Quality Criteria of Differently Manufactured Silver Powders'''</caption> {| class="twocolortable" style="text-align: left; font-size: 12px"|-!colspan="2" |Impurities !Ag-Chem.46*!Ag-ES**!Ag-V***|-|Cu |ppm|< 100|< 300|< 300|-|Fe |ppm|< 50|< 100|< 100|-|Ni |ppm|< 50|< 50|< 50|-|Cd |ppm|||< 50|-|Zn |ppm|||< 10|-|Na + K + Mg + Ca |ppm|< 80|< 50|< 50|-|Ag CI |ppm|< 500|< 500|< 500|-|NO₃ |ppm|< 40|< 40||-|Nh₄CI |ppm|< 30|< 30||-!colspan="5" |Particle Size Distribution (screen analysis)|-|> 100 μm |%|0|0|0|-|< 100 bis > 63 μm |%|< 5|< 5|< 15|-|< 36 μm |%|< 80|< 90|< 75|-|Apparent Density |g/cm³|1.0 - 1.6|1.0 - 1.5|3 - 4|-|Tap Density |ml/100g|40 - 50|40 - 50|15 - 25|-!colspan="5" |Press/Sintering Behavior|-|Press Density |g/cm³|5.6 - 6.5|5.6 - 6.3|6.5 - 8.5|-|Sinter Density |g/cm³|> 9|> 9.3|> 8|-|Volume Shrinkage |%|> 34|> 35|> 0|-|Annealing Loss|%|< 2|< 0.1|< 0.1|}</figtable> <nowiki>*</nowiki> Manufactured by chemical precipitation <br /><nowiki>**</nowiki> Manufactured by electrolytic deposition <br /><nowiki>***</nowiki> Manufactured by atomizing of a melt  <div class="multiple-images"> <figure id="fig:Strain hardening of Ag bei cold working">[[File: Softening Strain hardening of Ag bei cold working.jpg|left|thumb|<caption>Strain hardening of Ag 99.95 - cold working</caption>]]</figure> <figure id="fig:Softening of Ag after annealing for 1 hr after different degrees of strain hardening">[[File:Softening of Ag after annealing after different degrees.jpg|rightleft|thumb|<caption>Softening of Ag 99.95 after annealing for 1 hr after different degrees of strain hardening</caption>]]</figure></div><div class="clear"></div>

To improve the physical and contact properties of fine silver , melt-metallurgical produced silver alloys are used ''(<xr id="tab:Physical Properties of Silver and Silver Alloys"/>)<!--(Table 2.13)''-->. By adding metal components , the mechanical properties such as hardness and tensile strength as well as typical contact properties such as erosion resistance, and resistance against material transfer in DC circuits are increased ''(<xr id="tab:Mechanical Properties of Silver and Silver Alloys"/>)<!--(Table 2.14)''-->. On the other hand however, other properties such as electrical conductivity and chemical corrosion resistance can be negatively impacted by alloying ''(Figs<xr id="fig:Influence of 1 10 atom of different alloying metals"/><!--(Fig. 2.47 )--> and <xr id="fig:Electrical resistivity p of AgCu alloys"/>)<!--(Fig. 2.48)-->. <figtable id="tab:Physical Properties of Silver and Silver Alloys"><caption>'''<!--Table 2.13:-->Physical Properties of Silver and Silver Alloys'''</caption> {| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material !Silver Content<br />[wt%]!Density<br />[g/cm³]!Melting Point<br />or Range<br />[°C]!Electrical<br />Resistivity<br />[μΩ·cm]!Electrical<br />Conductivity<br />[MS/m]!Thermal<br />Conductivity<br />[W/mK]!Temp. Coefficient of<br />the Electr.Resistance<br />[10^-3/K]!Modulus of<br />Elasticity<br />[GPa]|-|Ag|99.95|10.5|961|1.67|60|419|4.1|80|-|AgNi0.15|99.85|10.5|960|1.72|58|414|4.0|82|-|AgCu3|97|10.4|900 - 938|1.92|52|385|3.2|85|-|AgCu5|95|10.4|910|1.96|51|380|3.0|85|-|AgCu10|90|10.3|870|2.0|50|335|2.8|85|-|AgCu28|72|10.0|779|2.08|48|325|2.7|92|-|Ag98CuNi<br />ARGODUR 27|98|10.4|940|1.92|52|385|3.5|85|-|AgCu24.5Ni0.5|75|10.0|805|2.20|45|330|2.7|92|-|Ag99.5NiMg<br />ARGODUR 32<br />Not heat treated|99.5|10.5|960|2.32|43|293|2.3|80|-|ARGODUR 32<br />Heat treated|99.5|10.5|960|2.32|43|293|2.1|80|}</figtable> <div class="multiple-images"> <figure id="fig:Influence of 1 10 atom of different alloying metals">[[File:Influence of 1 10 atom of different alloying metals.jpg|left|thumb|<caption>Influence of 1-10 atom% of different alloying metals on the electrical resistivity of silver</caption>]]</figure> <figure id="fig:Electrical resistivity p of AgCu alloys">[[File:Electrical resistivity p of AgCu alloys.jpg|left|thumb|<caption>Electrical resistivity p of AgCu alloys with 0-20 weight% Cu in the soft annealed and tempered stage a) Annealed and quenched b) Tempered at 280°C</caption>]]</figure></div><div class="clear"></div> <figtable id="tab:Mechanical Properties of Silver and Silver Alloys"><caption>'''<!--Table 2.14:-->Mechanical Properties of Silver and Silver Alloys'''</caption><table class="twocolortable"><tr><th><p class="s12">Material</p></th><th><p class="s12">Hardness</p><p class="s12">Condition</p></th><th><p class="s12">Tensile Strength</p><p class="s12">R<span class="s31">m </span>[MPa]</p></th><th><p class="s12">Elongation A [%] min.</p></th><th><p class="s12">Vickers Hardness</p><p class="s12">HV 10</p></th></tr><tr><td><p class="s12">Ag</p></td><td><p class="s12">R 200</p><p class="s12">R 250</p><p class="s12">R 300</p><p class="s12">R 360</p></td><td><p class="s12">200 - 250</p><p class="s12">250 - 300</p><p class="s12">300 - 360</p><p class="s12">&gt; 360</p></td><td><p class="s12">30</p><p class="s12">8</p><p class="s12">3</p><p class="s12">2</p></td><td><p class="s12">30</p><p class="s12">60</p><p class="s12">80</p><p class="s12">90</p></td></tr><tr><td><p class="s12">AgNi0.15</p><p class="s12"></p></td><td><p class="s12">R 220</p><p class="s12">R 270</p><p class="s12">R 320</p><p class="s12">R 360</p></td><td><p class="s12">220 - 270</p><p class="s12">270 - 320</p><p class="s12">320 - 360</p><p class="s12">&gt; 360</p></td><td><p class="s12">25</p><p class="s12">6</p><p class="s12">2</p><p class="s12">1</p></td><td><p class="s12">40</p><p class="s12">70</p><p class="s12">85</p><p class="s12">100</p></td></tr><tr><td><p class="s12">AgCu3</p></td><td><p class="s12">R 250</p><p class="s12">R 330</p><p class="s12">R 400</p><p class="s12">R 470</p></td><td><p class="s12">250 - 330</p><p class="s12">330 - 400</p><p class="s12">400 - 470</p><p class="s12">&gt; 470</p></td><td><p class="s12">25</p><p class="s12">4</p><p class="s12">2</p><p class="s12">1</p></td><td><p class="s12">45</p><p class="s12">90</p><p class="s12">115</p><p class="s12">120</p></td></tr><tr><td><p class="s12">AgCu5</p></td><td><p class="s12">R 270</p><p class="s12">R 350</p><p class="s12">R 460</p><p class="s12">R 550</p></td><td><p class="s12">270 - 350</p><p class="s12">350 - 460</p><p class="s12">460 - 550</p><p class="s12">&gt; 550</p></td><td><p class="s12">20</p><p class="s12">4</p><p class="s12">2</p><p class="s12">1</p></td><td><p class="s12">55</p><p class="s12">90</p><p class="s12">115</p><p class="s12">135</p></td></tr><tr><td><p class="s12">AgCu10</p></td><td><p class="s12">R 280</p><p class="s12">R 370</p><p class="s12">R 470</p><p class="s12">R 570</p></td><td><p class="s12">280 - 370</p><p class="s12">370 - 470</p><p class="s12">470 - 570</p><p class="s12">&gt; 570</p></td><td><p class="s12">15</p><p class="s12">3</p><p class="s12">2</p><p class="s12">1</p></td><td><p class="s12">60</p><p class="s12">95</p><p class="s12">130</p><p class="s12">150</p></td></tr><tr><td><p class="s12">AgCu28</p></td><td><p class="s12">R 300</p><p class="s12">R 380</p><p class="s12">R 500</p><p class="s12">R 650</p></td><td><p class="s12">300 - 380</p><p class="s12">380 - 500</p><p class="s12">500 - 650</p><p class="s12">&gt; 650</p></td><td><p class="s12">10</p><p class="s12">3</p><p class="s12">2</p><p class="s12">1</p></td><td><p class="s12">90</p><p class="s12">120</p><p class="s12">140</p><p class="s12">160</p></td></tr><tr><td><p class="s12">Ag98CuNi</p><p class="s12">ARGODUR 27</p></td><td><p class="s12">R 250</p><p class="s12">R 310</p><p class="s12">R 400</p><p class="s12">R 450</p></td><td><p class="s12">250 - 310</p><p class="s12">310 - 400</p><p class="s12">400 - 450</p><p class="s12">&gt; 450</p></td><td><p class="s12">20</p><p class="s12">5</p><p class="s12">2</p><p class="s12">1</p></td><td><p class="s12">50</p><p class="s12">85</p><p class="s12">110</p><p class="s12">120</p></td></tr><tr><td><p class="s12">AgCu24,5Ni0,5</p></td><td><p class="s12">R 300</p><p class="s12">R 600</p></td><td><p class="s12">300 - 380</p><p class="s12">&gt; 600</p></td><td><p class="s12">10</p><p class="s12">1</p></td><td><p class="s12">105</p><p class="s12">180</p></td></tr><tr><td><p class="s12">Ag99,5NiMg</p><p class="s12">ARGODUR 32</p><p class="s12">Not heat treated</p></td><td><p class="s12">R 220</p><p class="s12">R 260</p><p class="s12">R 310</p><p class="s12">R 360</p></td><td><p class="s12">220</p><p class="s12">260</p><p class="s12">310</p><p class="s12">360</p></td><td><p class="s12">25</p><p class="s12">5</p><p class="s12">2</p><p class="s12">1</p></td><td><p class="s12">40</p><p class="s12">70</p><p class="s12">85</p><p class="s12">100</p></td></tr><tr><td><p class="s12">ARGODUR 32 Heat treated</p></td><td><p class="s12">R 400</p></td><td><p class="s12">400</p></td><td><p class="s12">2</p></td><td><p class="s12">130-170</p></td></tr></table></figtable>

Fine-Grain Silver (ARGODUR-Spezial) silver is defined as a silver alloy with an addition of 0.15 wt% of Nickelnickel. Silver and nickel are not soluble in each other in solid form. In liquid silver , only a small amount of nickel is soluble as the phase diagram ''illustrates (<xr id="fig:Phase diagram of silver nickel"/><!--(Fig. 2.51)'' illustrates-->). During solidification of the melt , this nickel addition gets finely dispersed in the silver matrix and eliminates the pronounce coarse grain growth after prolonged influence of elevated temperatures ''(Figs<xr id="fig:Coarse grain micro structure of Ag"/><!--(Fig. 2.49 )--> and <xr id="fig:Fine grain microstructure of AgNiO"/><!--(Fig. 2.50)''-->).

Fig. 2.50<figure id="fig: Fine Coarse grain microstructure micro structure of AgNi0.15 after 80% cold working and 1 hr annealing at 600°CAg">[[File:Fine Coarse grain microstructure micro structure of AgNiOAg.jpg|rightleft|thumb|Fine <caption>Coarse grain microstructure micro structure of AgNi0Ag 99.15 97 after 80% cold working and 1 hr annealing at 600°C</caption>]]</figure>

<figure id="fig:Fine grain microstructure of AgNiO">[[File:Fine grain microstructure of AgNiO.jpg|left|thumb|<caption>Fine grain microstructure of AgNi0.15 after 80% cold working and 1 hr annealing at 600°C</caption>]]</figure> <figure id="fig:Phase diagram of silver nickel">[[File:Phase diagram of silver nickel.jpg|left|thumb|<caption>Phase diagram of silver nickel</caption>]]</figure></div><div class="clear"></div> Fine-grain Grain silver has almost the same chemical corrosion resistance as fine silver. Compared to pure silver , it exhibits a slightly increased hardness andtensile strength ''(<xr id="tab:Mechanical Properties of Silver and Silver Alloys"/><!--(Table 2.14)''-->). The electrical conductivity is just slightly decreased by this low nickel addition. Because of its significantly improved contact properties , fine grain silver has replaced pure silver in many applications.

Using copper as an alloying component increases the mechanical stability of silver significantly(<xr id="fig:Strain hardening of AgCu3 by cold working"/>, <xr id="fig:Softening of AgCu3 after annealing"/> and <xr id="fig:Strain hardening of AgCu5 by cold working"/>). The most important among the binary AgCu alloys is that of AgCu3, known in europe also under the name of known as hard-silver. This material still has a chemical corrosion resistance close to that of fine silver. In comparison to pure silver and fine-grain silver , AgCu3 exhibits increased mechanical strength as well as higher arc erosion resistance and mechanical wear resistance ''(Table 2.14)''.

Increasing the Cu content further also increases the mechanical strength of AgCu alloys and improves arc erosion resistance and resistance against material transfer while at the same time however simultaneously the tendency to oxide formation becomes detrimental. This causes - during switching under arcing conditions - an increase in contact resistance with rising numbers of operation. In special applications , where highest mechanical strength is recommended and a reduced chemical resistance can be tolerated, the eutectic AgCu alloy with 28 wt% of copper ''is used (<xr id="fig:Phase diagram of silver copper"/>)<!--(Fig. 2.52)'' is used-->. AgCu10 , also known as coin silver , has been replaced in many applications by composite silver-based materials while sterling silver (AgCu7.5) has never extended its important usage from decorative table wear and jewelry to industrial applications in electrical contacts.

Besides these binary alloys, ternary AgCuNi alloys are used in electrical contact applications. From this group , the material ARGODUR 27, an alloy of 98 wt% Ag with a 2 wt% Cu and nickel addition has found practical importance close to that of AgCu3. This material is characterized by high resistance to oxidation and low tendency to re-crystallization during exposure to high temperatures. Besides high mechanical stability this AgCuNi alloy also exhibits a strong resistance against arc erosion. Because of its high resistance against material transfer , the alloy AgCu24.5Ni0.5 has been used in the automotive industry for an extended time in the North American market. Caused by miniaturization and the related reduction in available contact forces in relays and switches , this material has been replaced widely because of its tendency to oxide formation.

Hard-silver alloys are widely used for switching applications in the information and energy technology for currents up to 10 A, in special cases also for higher current ranges ''(<xr id="tab:Application Examples and Forms of Supply for Silver and Silver Alloys"/>)<!--(Table 2.16)''-->. Dispersion hardened alloys of silver with 0.5 wt% MgO and NiO (ARGODUR 32) are produced by internal oxidation. While the melt-metallurgical alloy is easy to cold-work and form, the material becomes very hard and brittle after dispersion hardening. Compared to fine silver and hard-silver, this material has a greatly improved temperature stability and can be exposed to brazing temperatures up to 800°C without decreasing its hardness and tensile strength.Because of these mechanical properties and its high electrical conductivity ARGODUR 32 is mainly used in the form of contact springs that are exposed to high thermal and mechanical stresses in relays and contactors for aeronautic applications. <div class="multiple-images">

Dispersion hardened alloys <figure id="fig:Phase diagram of silver with 0copper"> [[File:Phase diagram of silver copper.5 wt% MgO and NiO (ARGODUR 32) are produced by internal oxidation. While the melt-metallurgical alloy is easy to cold-work and form the material becomes very hard and brittle after dispersion hardening. Compared to fine jpg|left|thumb|<caption>Phase diagram of silver and hard-silver this material has a greatly improved temperature stability and can be exposed to brazing temperatures up to 800°C without decreasing its hardness and tensile strength.copper</caption>]]Because of these mechanical properties and its high electrical conductivity ??? ARGODUR 32 is mainly used in the form of contact springs that are exposed to high thermal and mechanical stresses in relays, and contactors for aeronautic applications.</figure>

'''Table 2<figure id="fig:Strain hardening of AgCu3 by cold working"> [[File:Strain hardening of AgCu3 by cold working.13: Physical Properties jpg|left|thumb|<caption>Strain hardening of Silver and Silver Alloys'''AgCu3 by cold working</caption>]]</figure>

Fig. 2.51<figure id="fig: Phase diagram Softening of silver-nickelAgCu3 after annealing"> [[File:Phase diagram Softening of silver nickelAgCu3 after annealing.jpg|rightleft|thumb|Phase diagram <caption>Softening of silver nickelAgCu3 after annealing for 1 hr after 80% cold working</caption>]]</figure>

Fig. 2.52: Phase diagram of silver-copper[[File:Phase diagram of silver copper.jpg|right|thumb|Phase diagram of silver-copper]]Fig. 2.53: Phase diagram of silver-cadmium[[File:Phase diagram of silver cadmium.jpg|right|thumb|Phase diagram of silver-cadmium]]Fig. 2.54<figure id="fig: Strain hardening of AgCu3 AgCu5 by cold working"> [[File:Strain hardening of AgCu3 AgCu5 by cold working.jpg|rightleft|thumb|<caption>Strain hardening of AgCu3 AgCu5 by cold working</caption>]]</figure>

'''Table 2.14: Mechanical Properties of Silver and Silver Alloys'''<table border="1" cellspacingfigure id="0" style="border-collapsefig:collapseSoftening of AgCu5 after annealing"><tr><td><p class="s12">Material/</p><p class="s12">DODUCO-Designation</p></td><td><p class="s12">Hardness</p><p class="s12">Condition</p></td><td><p class="s12">Tensile Strength</p><p class="s12">R<span class="s31">m </span>[MPa]</p></td><td><p class="s12">Elongation A [%] minFile:Softening of AgCu5 after annealing.jpg|left|thumb|</p></td><td><p class="s12">Vickers Hardness</p><p class="s12">HV 10</p></td></tr><tr><td><p class="s12">Ag</p></td><td><p class="s12">R 200</p><p class="s12">R 250</p><p class="s12">R 300</p><p class="s12">R 360</p></td><td><p class="s12">200 - 250</p><p class="s12">250 - 300</p><p class="s12">300 - 360</p><p class="s12">&gt; 360</p></td><td><p class="s12">30</p><p class="s12">8</p><p class="s12">3</p><p class="s12">2</p></td><td><p class="s12">30</p><p class="s12">60</p><p class="s12">80</p><p class="s12">90</p></td></tr><tr><td><p class="s12">AgNi 0,15</p><p class="s12">ARGODUR Special</p></td><td><p class="s12">R 220</p><p class="s12">R 270</p><p class="s12">R 320</p><p class="s12">R 360</p></td><td><p class="s12">220 - 270</p><p class="s12">270 - 320</p><p class="s12">320 - 360</p><p class="s12">&gt; 360</p></td><td><p class="s12">25</p><p class="s12">6</p><p class="s12">2</p><p class="s12">1</p></td><td><p class="s12">40</p><p class="s12">70</p><p class="s12">85</p><p class="s12">100</p></td></tr><tr><td><p class="s12">AgCu3</p></td><td><p class="s12">R 250</p><p class="s12">R 330</p><p class="s12">R 400</p><p class="s12">R 470</p></td><td><p class="s12">250 - 330</p><p class="s12">330 - 400</p><p class="s12">400 - 470</p><p class="s12">&gt; 470</p></td><td><p class="s12">25</p><p class="s12">4</p><p class="s12">2</p><p class="s12">1</p></td><td><p class="s12">45</p><p class="s12">90</p><p class="s12">115</p><p class="s12">120</p></td></tr><tr><td><p class="s12"caption>Softening of AgCu5</p></td><td><p class="s12">R 270</p><p class="s12">R 350</p><p class="s12">R 460</p><p class="s12">R 550</p></td><td><p class="s12">270 - 350</p><p class="s12">350 - 460</p><p class="s12">460 - 550</p><p class="s12">&gt; 550</p></td><td><p class="s12">20</p><p class="s12">4</p><p class="s12">2</p><p class="s12">after annealing for 1hr after 80% cold working</p></td><td><p class="s12">55</p><p class="s12">90</p><p class="s12">115</p><p class="s12">135</p></td></tr><tr><td><p class="s12">AgCu10</p></td><td><p class="s12">R 280</p><p class="s12">R 370</p><p class="s12">R 470</p><p class="s12">R 570</p></td><td><p class="s12">280 - 370</p><p class="s12">370 - 470</p><p class="s12">470 - 570</p><p class="s12">&gt; 570</p></td><td><p class="s12">15</p><p class="s12">3</p><p class="s12">2</p><p class="s12">1</p></td><td><p class="s12">60</p><p class="s12">95</p><p class="s12">130</p><p class="s12">150</p></td></tr><tr><td><p class="s12">AgCu28</p></td><td><p class="s12">R 300</p><p class="s12">R 380</p><p class="s12">R 500</p><p class="s12">R 650</p></td><td><p class="s12">300 - 380</p><p class="s12">380 - 500</p><p class="s12">500 - 650</p><p class="s12">&gt; 650</p></td><td><p class="s12">10</p><p class="s12">3</p><p class="s12">2</p><p class="s12">1</p></td><td><p class="s12">90</p><p class="s12">120</p><p class="s12">140</p><p class="s12">160</p></td></tr><tr><td><p class="s12">Ag98CuNi</p><p class="s12">ARGODUR 27</p></td><td><p class="s12">R 250</p><p class="s12">R 310</p><p class="s12">R 400</p><p class="s12">R 450</p></td><td><p class="s12">250 - 310</p><p class="s12">310 - 400</p><p class="s12">400 - 450</p><p class="s12">&gt; 450</p></td><td><p class="s12">20</p><p class="s12">5</p><p class="s12">2</p><p class="s12">1</p></td><td><p class="s12">50</p><p class="s12">85</p><p class="s12">110</p><p class="s12">120</p></td></tr><tr><td><p class="s12">AgCu24,5Ni0,5</p></td><td><p class="s12">R 300</p><p class="s12">R 600</p></td><td><p class="s12">300 - 380</p><p class="s12">&gt; 600</p></td><td><p class="s12">10</p><p class="s12">1</p></td><td><p class="s12">105</p><p class="s12">180</p></td></tr><tr><td><p class="s12">AgCd10</p></td><td><p class="s12">R 200</p><p class="s12">R 280</p><p class="s12">R 400</p><p class="s12">R 450</p></td><td><p class="s12">200 - 280</p><p class="s12">280 - 400</p><p class="s12">400 - 450</p><p class="s12">&gt; 450</p></td><td><p class="s12">15</p><p class="s12">3</p><p class="s12">2</p><p class="s12">1</p></td><td><p class="s12">36</p><p class="s12">75</p><p class="s12">100</p><p class="s12">115</p></td></tr><tr><td><p class="s12">Ag99,5NiMg</p><p class="s12">ARGODUR 32</p><p class="s12">Not heat treated</p></td><td><p class="s12">R 220</p><p class="s12">R 260</p><p class="s12">R 310</p><p class="s12">R 360</p></td><td><p class="s12">220</p><p class="s12">260</p><p class="s12">310</p><p class="s12">360</p></td><td><p class="s12">25</p><p class="s12">5</p><p class="s12">2</p><p class="s12">1</p></td><td><p class="s12">40</p><p class="s12">70</p><p class="s12">85</p><p class="s12">100</p></td></tr><tr><td><p class="s12">ARGODUR 32 Heat treated</p></td><td><p class="s12">R 400</p></td><td><p class="s12">400</p></td><td><p class="s12">2</p></td><td><p class="s12">130-170</p></td></trcaption>]]</tablefigure>

Fig. 2.55: Softening of AgCu3 after annealing for 1 hr after 80% cold working[[File:Softening of AgCu3 after annealing.jpg|right|thumb|Softening of AgCu3 after annealing for 1 hr after 80% cold working]]Fig. 2.56: Strain hardening of AgCu5 by cold working[[File:Strain hardening of AgCu5 by cold working.jpg|right|thumb|Strain hardening of AgCu5 by cold working]]Fig. 2.57: Softening of AgCu5 after annealing for 1 hr after 80% cold working[[File:Softening of AgCu5 after annealing.jpg|right|thumb|Softening of AgCu5 after annealing for 1 hr after 80% cold working]]Fig. 2.58<figure id="fig: Strain hardening of AgCu 10 by cold working"> [[File:Strain hardening of AgCu 10 by cold working.jpg|rightleft|thumb|<caption>Strain hardening of AgCu 10 by cold working</caption>]]Fig. 2.59: Softening of AgCu10 after annealing for 1 hr after 80% cold working[[File:Softening of AgCu10 after annealing.jpg|right|thumb|Softening of AgCu10 after annealing for 1 hr after 80% cold working]]Fig. 2.60: Strain hardening of AgCu28 by cold working[[File:Strain hardening of AgCu28 by cold working.jpg|right|thumb|Strain hardening of AgCu28 by cold working]]Fig. 2.61: Softening of AgCu28 after annealing for 1 hr after 80% cold working[[File:Softening of AgCu28 after annealing.jpg|right|thumb|Softening of AgCu28 after annealing for 1 hr after 80% cold working]]Fig. 2.62: Strain hardening of AgNi0.15 by cold working[[File:Strain hardening of AgNiO15 by cold working.jpg|right|thumb|Strain hardening of AgNiO15 by cold working]]Fig. 2.63: Softening of AgNi0.15 after annealing for 1 hr after 80% cold working[[File:Softening of AgNiO15 after annealing.jpg|right|thumb|Softening of AgNiO15 after annealing]]Fig. 2.64: Strain hardening of ARGODUR 27 by cold working[[File:Strain hardening of ARGODUR 27.jpg|right|thumb|Strain hardening of ARGODUR 27 by cold working]]Fig. 2.65: Softening of ARGODUR 27 after annealing for 1 hr after 80% cold working[[File:Softening of ARGODUR 27 after annealing.jpg|right|thumb|Softening of ARGODUR 27 after annealing for 1 hr after 80% cold working]]Table 2.15: Contact and Switching Properties of Silver and Silver Alloys</figure>

<figure id="fig:Softening of AgCu10 after annealing"> [[File:Softening of AgCu10 after annealing.jpg|left|thumb|<caption>Softening of AgCu10 after annealing for 1 hr after 80% cold working</caption>]]</figure>  <figure id="fig:Strain hardening of AgCu28 by cold working"> [[File:Strain hardening of AgCu28 by cold working.jpg|left|thumb|<caption>Strain hardening of AgCu28 by cold working</caption>]]</figure>  <figure id="fig:Softening of AgCu28 after annealing"> [[File:Softening of AgCu28 after annealing.jpg|left|thumb|<caption>Softening of AgCu28 after annealing for 1 hr after 80% cold working</caption>]]</figure>  <figure id="fig:Strain hardening of AgNi0.15 by cold working"> [[File:Strain hardening of AgNiO15 by cold working.jpg|left|thumb|<caption>Strain hardening of AgNiO15 by cold working</caption>]]</figure>  <figure id="fig:Softening of AgNi0.15 after annealing"> [[File:Softening of AgNiO15 after annealing.jpg|left|thumb|<caption>Softening of AgNiO15 after annealing</caption>]]</figure>  <figure id="fig:Strain hardening of ARGODUR 27"> [[File:Strain hardening of ARGODUR 27.jpg|left|thumb|<caption>Strain hardening of AgCu1.8Ni0.2 (ARGODUR 27) by cold working</caption>]]</figure>  <figure id="fig:Softening of ARGODUR 27 after annealing"> [[File:Softening of ARGODUR 27 after annealing.jpg|left|thumb|<caption>Softening of AgCu1.8Ni0.2 (ARGODUR 27) after annealing for 1 hr after 80% cold working</caption>]]</figure></div><div class="clear"></div>   <figtable id="tab:Contact and Switching Properties of Silver and Silver Alloys"><caption>'''<!--Table 2.15:-->Contact and Switching Properties of Silver and Silver Alloys'''</caption> {| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material !colspan="2" | Properties|-|Ag<br />AgNi0.15|Highest electrical and thermal conductivity, high affinity to sulfur (sulfide formation), low welding resistance, low contact resistance, very good formability |Oxidation resistant at higher make currents, limited arc erosion resistance, tendency to material transfer in DC circuits, easy to braze and weld to carrier materials|-|Ag Alloys |Increasing contact resistance with increasingCu content, compared to fine Ag higher arc erosion resistance and mechanical strength, lower tendency to material transfer|Good formability, good brazing and welding properties |}</figtable>  <figtable id="tab:Application Examples and Forms of Supply for Silver and Silver Alloys"><caption>'''<!--Table 2.16: -->Application Examples and Forms of Supply for Silver and Silver Alloys'''</caption> {| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material !Application Examples!Form of Supply|-|Ag<br />AgNi0.15<br />AgCu3<br />AgNi98NiCu2<br />ARGODUR 27<br />AgCu24,5Ni0,5|Relays,<br />Micro switches,<br />Auxiliary current switches,<br />Control circuit devices,<br />Appliance switches,<br />Wiring devices (&le; 20A),<br />Main switches |'''Semi-finished Materials:''' <br />Strips, wires, contact profiles, clad contact strips, toplay profiles, seam- welded strips<br />'''Contact Parts:'''<br />Contact tips, solid and composite rivets, weld buttons; clad, welded and riveted contact parts|-|AgCu5<br />AgCu10<br />AgCu28 |Special applications|'''Semi-finished Materials:'''<br />Strips, wires, contact profiles, clad contact strips, seam-welded strips<br />'''Contact parts:'''<br />Contact tips, solid contact rivets, weld buttons; clad, welded and riveted contact parts|-|Ag99.5NiOMgO<br />ARGODUR 32|Miniature relays, aerospace relays and contactors, erosion wire for injection nozzles|Contact springs, contact carrier parts |}</figtable>

The addition of 30 wt% Pd increases the mechanical properties as well as the resistance of silver against the influence of sulfur and sulfur containingcompounds significantly ''(Tables <xr id="tab:Physical Properties of Silver-Palladium Alloys"/><!--(Tab 2.17 )--> and <xr id="tab:Mechanical Properties of Silver-Palladium Alloys"/>)<!--(Tab.2.18)''-->. Alloys with 40-60 wt% Pd have an even higher resistance against silver sulfide formation. At these percentage ranges however , the catalytic properties of palladium can influence the contact resistance behavior negatively. The formability also decreases with increasing Pd contents. AgPd alloys are hard, arc erosion resistant, and have a lower tendency towards material transfer under DC loads (<xr id="tab:Contact and Switching Properties of Silver-Palladium Alloys"/>)<!--(Table 2.19)-->. On the other hand, the electrical conductivity is decreased at higher Pd contents. The ternary alloy AgPd30Cu5 has an even higher hardness, which makes it suitable for use in sliding contact systems. AgPd alloys are mostly used in relays for the switching of medium to higher loads (> 60V, > 2A) as shown in <xr id="tab:Application Examples and Forms of Suppl for Silver-Palladium Alloys"/><!--(Table 2.20)-->. Because of the high palladium price, these formerly solid contacts have been widely replaced by multi-layer designs such as AgNi0.15 or AgNi10 with a thin Au surface layer. A broader field of application for AgPd alloys remains in the wear resistant sliding contact systems.  <div class="multiple-images"><figure id="fig:Phase diagram of silver palladium">[[File:Phase diagram of silver palladium.jpg|left|thumb|<caption>Phase diagram of silver-palladium</caption>]]</figure> <figure id="fig:Strain hardening of AgPd30 by cold working">[[File:Strain hardening of AgPd30 by cold working.jpg|left|thumb|<caption>Strain hardening of AgPd30 by cold working</caption>]]</figure> <figure id="fig:Strain hardening of AgPd50 by cold working">[[File:Strain hardening of AgPd50 by cold working.jpg|left|thumb|<caption>Strain hardening of AgPd50 by cold working</caption>]]</figure> <figure id="fig:Strain hardening of AgPd30Cu5 by cold working">[[File:Strain hardening of AgPd30Cu5 by cold working.jpg|left|thumb|<caption>Strain hardening of AgPd30Cu5 by cold working</caption>]]</figure> <figure id="fig:Softening of AgPd30 AgPd50 AgPd30Cu5">[[File:Softening of AgPd30 AgPd50 AgPd30Cu5.jpg|left|thumb|<caption>Softening of AgPd30, AgPd50, and AgPd30Cu5 after annealing of 1 hr after 80% cold working</caption>]]</figure></div><div class="clear"></div>  <figtable id="tab:Physical Properties of Silver-Palladium Alloys"> <caption>'''<!--Table 2.17:--> Physical Properties of Silver-Palladium Alloys'''</caption>

AgPd alloys are hard, arc erosion resistant, and have a lower tendency towards material transfer under DC loads ''(Table {| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material!Palladium Content<br />[wt%]!Density<br />[g/cm³]!Melting Point<br />or Range<br />[°C]!Electrical<br />Resistivity<br />[μΩ·cm]!Electrical<br />Conductivity<br />[MS/m]!Thermal<br />Conductivity<br />[W/m·K]!Temp. Coefficient of<br />the Electr. Resistance<br />[10^-3/K]|-|AgPd30|30|10.9|1155 - 1220|14.7|6.8|60|0.4|-|AgPd40|40|11.1|1225 - 1285|20.8|4.8|46|0.36|-|AgPd50|50|11.2|1290 - 1340|32.3|3.1|34|0.23|-|AgPd60|60|11.19)''4|1330 - 1385|41. On the other hand the electrical conductivity is decreased at higher Pd contents7|2.4|29|0. The ternary alloy 12|-|AgPd30Cu5 has an even higher hardness which makes it suitable for use in sliding contact systems|30|10.8|1120 - 1165|15.6|6.4|28|0.37|}</figtable>

Fig. 2.66<figtable id="tab: Phase diagram Mechanical Properties of silverSilver-palladiumPalladium Alloys">[[File:Phase diagram of silver palladium.jpg|right|thumb|Phase diagram of silver<caption>'''<!--palladium]]Fig. Table 2.6718: Strain hardening -->Mechanical Properties of AgPd30 by cold workingSilver-Palladium Alloys'''</caption><table class="twocolortable"><tr><th><p class="s12">Material</p></th><th><p class="s12">Hardness</p><p class="s12">Condition</p></th><th><p class="s12">Tensile Strength</p><p class="s12">R<span class="s31">_m</span>[MPa]</p></th><th><p class="s12">Elongation A</p><p class="s12">[File:Strain hardening of AgPd30 by cold working%]min.jpg|right|thumb|Strain hardening of </p></th><th><p class="s12">Vickers Hardness</p><p class="s12">HV</p></th></tr><tr><td><p class="s12">AgPd30 by cold working]]Fig. </p></td><td><p class="s12">R 320</p><p class="s12">R 570</p></td><td><p class="s12">320</p><p class="s12">570</p></td><td><p class="s12">38</p><p class="s12">3</p></td><td><p class="s12">65</p><p class="s12">145</p></td></tr><tr><td><p class="s12">AgPd40</p></td><td><p class="s12">R 350</p><p class="s12">R 630</p></td><td><p class="s12">350</p><p class="s12">630</p></td><td><p class="s12">38</p><p class="s12">2.68: Strain hardening of </p></td><td><p class="s12">72</p><p class="s12">165</p></td></tr><tr><td><p class="s12">AgPd50 by cold working[[File:Strain hardening of AgPd50 by cold working.jpg|right|thumb|Strain hardening of AgPd50 by cold working]]Fig. </p></td><td><p class="s12">R 340</p><p class="s12">R 630</p></td><td><p class="s12">340</p><p class="s12">630</p></td><td><p class="s12">35</p><p class="s12">2</p></td><td><p class="s12">78</p><p class="s12">185</p></td></tr><tr><td><p class="s12">AgPd60</p></td><td><p class="s12">R 430</p><p class="s12">R 700</p></td><td><p class="s12">430</p><p class="s12">700</p></td><td><p class="s12">30</p><p class="s12">2.69: Strain hardening of </p></td><td><p class="s12">85</p><p class="s12">195</p></td></tr><tr><td><p class="s12">AgPd30Cu5 by cold working[[File:Strain hardening of AgPd30Cu5 by cold working.jpg|right|thumb|Strain hardening of AgPd30Cu5 by cold working]]Fig. </p></td><td><p class="s12">R 410</p><p class="s12">R 620</p></td><td><p class="s12">410</p><p class="s12">620</p></td><td><p class="s12">40</p><p class="s12">2.70: Softening of AgPd30, AgPd50, and AgPd30Cu5 after annealing of 1 hr after 80% cold working</p></td><td><p class="s12">90</p><p class="s12">190</p></td></tr></table>[[File:Softening of AgPd30 AgPd50 AgPd30Cu5.jpg|right|thumb|Softening of AgPd30, AgPd50, and AgPd30Cu5 after annealing of 1 hr after 80% cold working]]'''Table 2.17: Physical Properties of Silver-Palladium Alloys'''</figtable>

<figtable id="tab:Contact and Switching Properties of Silver-Palladium Alloys"><caption>'''<!--Table 2.19:-->Contact and Switching Properties of Silver-Palladium Alloys''</caption>' {| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material !colspan="2" | Properties|-|AgPd30-60|Corrosion resistant, tendency to Brown Powder formation increases with Pd content, low tendency to material transfer in DC circuits, high ductility |Resistant against Ag₂S formation, low contact resistance, increasing hardness with higher Pd content, AgPd30 has highest arc erosion resistance, easy to weld and clad|-|AgPd30Cu5 |High mechanical wear resistance|High Hardness |}</figtable>  <figtable id="tab:Application Examples and Forms of Suppl for Silver-Palladium Alloys"><caption>'''<!--Table 2.20: -->Application Examples and Forms of Suppl for Silver-Palladium Alloys'''</caption><table borderclass="1" cellspacing="0" style="border-collapse:collapsetwocolortable"><tr><tdth><p class="s12">Material</p></tdth><tdth><p class="s12">Application Examples</p></tdth><tdth><p class="s12">Form of Supply</p></tdth></tr><tr><td><p class="s12">AgPd 30-60</p></td><td><p class="s12">Switches, relays, push-buttons,</p><p class="s12">connectors, sliding contacts</p></td><td><p class="s12">'''Semi-finished Materials:'''</p><p class="s12">Wires, micro profiles (weld tapes), clad</p><p class="s12">contact strips, seam-welded strips</p><p class="s12">'''Contact Parts:'''</p><p class="s12">Solid and composite rivets, weld buttons;</p><p class="s12">clad and welded contact parts, stamped parts</p></td></tr><tr><td><p class="s12">AgPd30Cu5</p></td><td><p class="s12">Sliding contacts, slider tracks</p></td><td><p class="s12">Wire-formed parts, contact springs, solid</p><p class="s12">and clad stamped parts</p></td></tr></table></figtable>

====Silver-Nickel (SINIDUR) Materials====Since silver and nickel are not soluble in each other in solid form and also show very limited solubility in the liquid phase have only very limited solubility , silver nickel composite materials with higher Ni contents can only be produced by powder metallurgy. During extrusion of sintered Ag/Ni billets into wires, strips and rods , the Ni particles embedded in the Ag matrix are stretched and oriented in the microstructure into a pronounced fiber structure ''(Figs<xr id="fig:Micro structure of AgNi9010"/><!--(Fig. 2.75)--> and <xr id="fig:Micro structure of AgNi 8020"/>)<!--(Fig. 2.76)--> The high density produced during hot extrusion, aids the arc erosion resistance of these materials (<xr id="tab:Physical Properties of Silver-Nickel (SINIDUR) Materials"/>)<!--(Tab 2.21)-->. The typical application of Ag/Ni contact materials is in devices for switching currents of up to 100A (<xr id="tab:Application Examples and Forms of Supply for Silver-Nickel (SINIDUR) Materials"/>)<!--(Table 2.24)-->. In this range, they are significantly more erosion resistant than silver or silver alloys. In addition, they exhibit with nickel contents < 20 wt% a low and over their operational lifetime consistent contact resistance and good arc moving properties. In DC applications Ag/Ni materials exhibit a relatively low tendency of material transfer distributed evenly over the contact surfaces (<xr id="tab:Contact and Switching Properties of Silver-Nickel (SINIDUR) Materials"/>)<!--(Table 2.23)-->. Typically Ag/Ni materials are usually produced with contents of 10-40 wt% Ni. The most common used materials Ag/Ni 10 and Ag/Ni 20- and also Ag/Ni 15, mostly used in north america-, are easily formable and applied by cladding (<xr id="fig:Strain hardening of AgNi9010 by cold working"/>,<!--(Fig. 2.71)--> <xr id="fig:Softening of AgNi9010 after annealing"/>,<!--(Fig. 2.72)--> <xr id="fig:Strain hardening of AgNi8020"/>, <!--(Fig. 2.73)--> <xr id="fig:Softening of AgNi8020 after annealing"/>)<!--(Fig. 2.74)-->. They can be, without any additional welding aids, economically welded and brazed to the commonly used contact carrier materials. The Ag/Ni materials with nickel contents of 30 and 40 wt% are used in switching devices, requiring a higher arc erosion resistance and where increases in contact resistance can be compensated through higher contact forces. The most important applications for Ag/Ni contact materials are typically in relays, wiring devices, appliance switches, thermostatic controls, auxiliary switches and small contactors with nominal currents > 20A (<xr id="tab:Application Examples and Forms of Supply for Silver-Nickel (SINIDUR) Materials"/>)<!--(Table 2.7624)-->. <figtable id="tab:Physical Properties of Silver-Nickel (SINIDUR) Materials"><caption>'''<!--Table 2.21:-->Physical Properties of Silver-Nickel Materials'''</caption><table class="twocolortable"><tr><th>Material</th><th>Silver Content</th><th>Density</th><th>Melting Point</th><th>ElectricalResistivity<i>p</i></th><th colspan="2">Electrical Resistivity (soft)</th></tr><tr><th></th><th>[wt%]</th><th>[g/cm³]</th><th>[°C]</th><th>[µΩ·cm]</th><th>[% IACS]</th><th>[MS/m]</th></tr><tr><td><p class="s11">Ag/Ni 90/10</p><p class="s11"></p></td><td><p class="s11">89 - 91</p></td><td><p class="s11">10.2 - 10.3</p></td><td><p class="s11">960</p></td><td><p class="s11">1.82 - 1.92</p></td><td><p class="s12">90 - 95</p></td><td><p class="s12">52 - 55</p></td></tr><tr><td><p class="s11">Ag/Ni 85/15</p><p class="s11"></p></td><td><p class="s11">84 - 86</p></td><td><p class="s11">10.1 - 10.2</p></td><td><p class="s11">960</p></td><td><p class="s11">1.89 - 2.0</p></td><td><p class="s12">86 - 91</p></td><td><p class="s12">50 - 53</p></td></tr><tr><td><p class="s11">Ag/Ni 80/20</p><p class="s11"></p></td><td><p class="s11">79 - 81</p></td><td><p class="s11">10.0 - 10.1</p></td><td><p class="s11">960</p></td><td><p class="s11">1.92 - 2.08</p></td><td><p class="s12">83 - 90</p></td><td><p class="s12">48 - 52</p></td></tr><tr><td><p class="s11">Ag/Ni 70/30</p><p class="s11"></p></td><td><p class="s11">69 - 71</p></td><td><p class="s11">9.8</p></td><td><p class="s11">960</p></td><td><p class="s11">2.44</p></td><td><p class="s12">71</p></td><td><p class="s12">41</p></td></tr><tr><td><p class="s11">Ag/Ni 60/40</p><p class="s11"></p></td><td><p class="s11">59 - 61</p></td><td><p class="s11">9.7</p></td><td><p class="s11">960</p></td><td><p class="s11">2.70</p></td><td><p class="s12">64</p></td><td><p class="s12">37</p></td></tr></table></figtable>  <figtable id="tab:tab2.22"><caption>'''<!-- Table 2.22:-->Mechanical Properties of Silver-Nickel Materials'''</caption> {| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material !Hardness Condition!Tensile Strength R_m [Mpa]!Elongation A (soft annealed) [%] min.!Vickers Hardness HV 10|-|Ag/Ni 90/10<br />|soft<br />R 220<br />R 280<br />R 340<br />R 400|< 250<br />220 - 280<br />280 - 340<br />340 - 400<br />> 400|25<br />20<br />3<br />2<br />1|< 50<br />50 - 70<br />65 - 90<br />85 - 105<br />> 100|-|Ag/Ni 85/15<br />|soft<br />R 300<br />R 350<br />R 380<br />R 400|< 275<br />250 - 300<br />300 - 350<br />350 - 400<br />> 400|20<br />4<br />2<br />2<br />1|< 70<br />70 - 90<br />85 - 105<br />100 - 120<br />> 115|-|Ag/Ni 80/20<br />|soft<br />R 300<br />R 350<br />R 400<br />R 450|< 300<br />300 - 350<br />350 - 400<br />400 - 450<br />> 450|20<br />4<br />2<br />2<br />1|< 80<br />80 - 95<br />90 - 110<br />100 - 125<br />> 120|-|Ag/Ni 70/30<br />|R 330<br />R 420<br />R 470<br />R 530|330 - 420<br />420 - 470<br />470 - 530<br />> 530|8<br />2<br />1<br />1|80<br />100<br />115<br />135|-|Ag/Ni 60/40<br />|R 370<br />R 440<br />R 500<br />R 580|370 - 440<br />440 - 500<br />500 - 580<br />> 580|6<br />2<br />1<br />1|90<br />110<br />130<br />150|}</figtable>  <div class="multiple-images"><figure id="fig:Strain hardening of AgNi9010 by cold working">[[File:Strain hardening of AgNi9010 by cold working.jpg|right|thumb|<caption>Strain hardening of Ag/Ni 90/10 by cold working</caption>]]</figure> <figure id="fig:Softening of AgNi9010 after annealing">[[File:Softening of AgNi9010 after annealing.jpg|right|thumb|<caption>Softening of Ag/Ni 90/10 after annealing for 1 hr after 80% cold working</caption>]]</figure> <figure id="fig:Strain hardening of AgNi8020">[[File:Strain hardening of AgNi8020.jpg|right|thumb|<caption>Strain hardening of Ag/Ni 80/20 by cold working</caption>]]</figure> <figure id="fig:Softening of AgNi8020 after annealing">[[File:Softening of AgNi8020 after annealing.jpg|right|thumb|<caption>Softening of Ag/Ni 80/20 after annealing for 1 hr after 80% cold working</caption>]]</figure>

The high density produced during hot extrusion aids the arc erosion resistance <figure id="fig:Micro structure of AgNi9010">[[File:Micro structure of these materials ''(Tables 2AgNi9010.21 and 2.22)''. The typical application jpg|right|thumb|<caption>Micro structure of Ag/Ni contact materials is in devices for switching currents of up 90/10 a) perpendicular to 100A ''(Table 2.24the extrusion direction b)''. In this range they are significantly more erosion resistant than silver or silver alloys. In addition they exhibit with nickel contents parallel to the extrusion direction</caption>]]<20 wt% a low and over their operational lifetime consistent contact resistance and good arc moving properties. In DC applications Ag/Ni materials exhibit a relatively low tendency of material transfer distributed evenly over the contact surfaces ''(Table 2.23)''.figure>

Typically <figure id="fig:Micro structure of AgNi 8020">[[File:Micro structure of AgNi 8020.jpg|right|thumb|<caption>Micro structure of Ag/Ni (SINIDUR80/20 a) materials are usually produced with contents of 10-40 wt% Ni. The most widely used materials SINIDUR 10 and SINIDUR 20- and also SINIDUR 15, mostly used in north america-, are easily formable and applied by cladding ''(Figs. 2.71-2.74perpendicular to the extrusion direction b)''. They can be, without any additional welding aids, economically welded and brazed parallel to the commonly used contact carrier materials.extrusion direction</caption>]]</figure>The (SINIDUR) materials with nickel contents of 30 and 40 wt% are used in switching devices requiring a higher arc erosion resistance and where increases</div>in contact resistance can be compensated through higher contact forces.<div class="clear"></div>

'''Table 2.21<figtable id="tab: Physical Contact and Switching Properties of Silver-Nickel (SINIDUR) Materials'''<table border="1" cellspacing="0" style="border-collapse:collapse"><trcaption>'''<td><p class="s12">Material/</p><p class="s11">DODUCO <span style=" color: #151616;">Designation</span></p></td><td><p class="s12">Silver Content</p><p class="s12">[wt%]</p></td><td><p class="s12">Density</p><p class="s11">[g/cm<span class="s13">3 </span><span style=" color: #151616;">]</span></p></td><td><p class="s12">Melting Point</p><p class="s12">[°C]</p></td><td><p class="s12">Electrical</p><p class="s12">Resistivity <i>p</i></p><p class="s11">[µ<span class="s14">S ·</span>cm]</p></td><td><p class="s12">Electrical Resistivity</p><p class="s11">(soft)</p></td></tr><tr><td><p class="s12">Material/</p><p class="s11">DODUCO <span style=" color: #151616;">Designation</span></p></td><td><p class="s12">Silver Content</p><p class="s12">[wt%]</p></td><td><p class="s12">Density</p><p class="s11">[g/cm<span class="s13">3 </span><span style=" color: #151616;">]</span></p></td><td><p class="s12">Melting Point</p><p class="s12">[°C]</p></td><td><p class="s12">Electrical</p><p class="s12">Resistivity <i>p</i></p><p class="s11">[µ<span class="s14">S ·</span>cm]</p></td><td><p class="s11">[% IACS]</p></td><td><p class="s11">[MS/m]</p></td></tr><tr><td><p class="s11">Ag/Ni 90/10</p><p class="s11">SINIDUR 10</p></td><td><p class="s11">89 !- 91</p></td><td><p class="s11">10.2 - 10.3</p></td><td><p class="s11">960</p></td><td><p class="s11">1.82 - 1.92</p></td><td><p class="s12">90 - 95</p></td><td><p class="s12">52 - 55</p></td></tr><tr><td><p class="s11">Ag/Ni 85/15</p><p class="s11">SINIDUR 15</p></td><td><p class="s11">84 - 86</p></td><td><p class="s11">10.1 - 10.Table 2</p></td><td><p class="s11">960</p></td><td><p class="s11">1.89 23:- 2.0</p></td><td><p class="s12">86 - 91</p></td><td><p class="s12">50 Contact and Switching Properties of Silver- 53</p></td></tr><tr><td><p class="s11">Ag/Ni 80/20</p><p class="s11">SINIDUR 20</p></td><td><p class="s11">79 - 81</p></td><td><p class="s11">10.0 - 10.1</p></td><td><p class="s11">960</p></td><td><p class="s11">1.92 - 2.08</p></td><td><p class="s12">83 - 90</p></td><td><p class="s12">48 - 52</p></td></tr><tr><td><p class="s11">Ag/Ni 70/30</p><p class="s11">SINIDUR 30</p></td><td><p class="s11">69 - 71</p></td><td><p class="s11">9.8</p></td><td><p class="s11">960</p></td><td><p class="s11">2.44</p></td><td><p class="s12">71</p></td><td><p class="s12">41</p></td></tr><tr><td><p class="s11">Ag/Ni 60/40</p><p class="s11">SINIDUR 40</p></td><td><p class="s11">59 - 61</p></td><td><p class="s11">9.7</p></td><td><p class="s11">960</p></td><td><p class="s11">2.70</p></td><td><p class="s12">64</p></td><td><p class="s12">37</p></td></tr>Nickel Materials'''</tablecaption>

'''Table 2.22{| class="twocolortable" style="text-align: Mechanical left; font-size: 12px"|-!Material !Properties |-|Ag/Ni <br />|High arc erosion resistance at switching currents up to 100A,<br />Resistance against welding for starting current up to 100A,<br />low and over the electrical contact life nearly constant contact resistance for Ag/Ni 90/10 and Ag/Ni 80/20,<br />ow and spread-out material transfer under DC load,<br />non-conductive erosion residue on isolating components resulting in only minor change of the dielectric strength of Silver-Nickel (SINIDUR) Materials'''switching devices,<br />good arc moving properties,<br />good arc extinguishing properties,<br />good or sufficient ductility depending on the Ni content,<br />easy to weld and braze|}</figtable>

<figtable id="tab:Application Examples and Forms of Supply for Silver-Nickel (SINIDUR) Materials"><caption>'''<!--Table 2.2324: Contact -->Application Examples and Switching Properties Forms of Supply for Silver-Nickel (SINIDUR) Materials'''</caption>

'''Table 2.24{| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material!Application Examples and Forms !Switching or Nominal Current!Form of Supply for Silver|-|Ag/Ni 90/10-80/20|Relays<br /> Automotive Relays -Nickel (SINIDUR) Resistive load - Motor load|> 10A<br />> 10A|rowspan="9" | '''Semi-finisched Materials:'''<br />Wires, profiles,<br />clad strips,<br />Seam-welded strips,<br />Toplay strips <br />'''Contact Parts:'''<br />Contact tips, solid<br />and composite<br />rivets, Weld buttons,<br />clad, welded,<br />brazed, and riveted<br />contact parts|-|Ag/Ni 90/10, Ag/Ni 85/15-80/20|Auxiliary current switches|&le; 100A|-|Ag/Ni 90/10-80/20|Appliance switches|&le; 50A|-|Ag/Ni 90/10|Wiring devices|&le; 20A|-|Ag/Ni 90/10|Main switches, Automatic staircase illumination switches|&le; 100A|-|Ag/Ni 90/10-80/20|Control<br />Thermostats|> 10A<br />&le; 50A|-|Ag/Ni 90/10-80/20|Load switches|&le; 20A|-|Ag/Ni 90/10-80/20|Contactors circuit breakers|&le; 100A|-|Ag/Ni 90/10-80/20<br />paired with Ag/C 97/3-96/4|Motor protective circuit breakers|&le; 40A|-|Ag/Ni 80/20-60/40<br />paired with Ag/C 96/4-95/5|Fault current circuit breakers|&le; 100A|rowspan="2" | Rods, Profiles,<br />Contact tips, Formed parts,<br />brazed and welded<br />contact parts|-|Ag/Ni 80/20-60/40<br />paired with Ag/C 96/4-95/5|Power switches|> 100A|}</figtable>

The family of silver-metal oxide contact materials includes the material groups: silver-cadmium oxide (DODURIT CdO), silver-tin oxide (SISTADOX), and silverzinc oxide (DODURIT ZnO). Because of their very good contact and switching properties like high resistance against welding, low contact resistance, and high arc erosion resistance, silver-metal oxides have gained an outstanding position in a broad field of applications. They are mainly are used in low voltage electrical switching devices like relays, installation and distribution switches, appliances, industrial controls, motor controls, and protective devices ''(<xr id="tab:Application Examples of Silver–Metal Oxide Materials"/>)<!--(Table 2.1331)''-->.

*'''Silver-cadmium oxide (DODURIT CdO) materials'''

Silver-cadmium oxide (DODURIT CdO) materials with 10-15 wt% are produced by both, internal oxidation and powder metallurgical methods ''(Table 2.25)''.

The manufacturing of strips and wires by internal oxidation starts with a molten alloy of silver and cadmium. During a heat treatment below it's melting point in a an oxygen rich atmosphere in of such a homogeneous alloy , the oxygen diffuses from the surface into the bulk of the material and oxidizes the Cd to CdO in a more or less fine particle precipitation inside the Ag matrix. The CdO particles are rather fine in the surface area and are becoming getting larger further away towards the center of the material ''(<xr id="fig:Micro structure of AgCdO9010"/>)<!--(Fig. 2.83)''-->.

During the manufacturing of Ag/CdO contact material by internal oxidation , the processes vary depending on the type of semi-finished material. For Ag/CdO wires , a complete oxidation of the AgCd wire is performed, followed by wire-drawing to the required diameter ''(<xr id="fig:Strain hardening of internally oxidized AgCdO9010"/><!--(Figs. 2.77 )--> and <xr id="fig:Softening of internally oxidized AgCdO9010"/>)<!--(Fig. 2.78)''-->. The resulting material is used for example , in the production of contact rivets. For Ag/CdO strip materials two processes are commonly used: Cladding of an AgCd alloy strip with fine silver , followed by complete oxidation , results in a strip material with a small depletion area in the center of it's thickness and a an Ag backing suitable for easy attachment by brazing (sometimes called “Conventional "Conventional Ag/CdO”CdO"). Using a technology that allows the partial oxidation of a dual-strip AgCd alloy material in a higher pressure pure oxygen atmosphere , yields a composite Ag/CdO strip material that has - besides a relatively fine CdO precipitation - also a an easily brazable AgCd alloy backing ''(Fig. 2.85)''. These materials (DODURIT CdO ZH) are mainly used as the basis for contact profiles and contact tips.

During powder metallurgical production , the powder mixed made by different processes are typically converted by pressing, sintering and extrusion to wiresand strips. The high degree of deformation during hot extrusion , produces a uniform and fine dispersion of CdO particles in the Ag matrix while at the same time achieving a high density which is advantageous for good contact properties ''(<xr id="fig:Micro structure of AgCdO9010P"/>)<!--(Fig. 2.84)''-->. To obtain a backing suitable for brazing, a fine silver layer is applied by either com-pound extrusion or hot cladding prior to or right after the extrusion ''(Fig. 2.86)''.

For larger contact tips, and especially those with a rounded shape, the single tip Press-Sinter-Repress process (PSR) offers economical advantages. Thepowder mix is pressed in into a die close to the final desired shape, the “green” "green" tips are sintered, and in most cases , the repress process forms the exact final exact shape while at the same time , increasing the contact density and hardness.

Using different silver powders and minor additives for the basic Ag and CdO , starting materials can help influence certain contact properties for specialized applications.

Fig. 2.77<div class="multiple-images"><figure id="fig: Strain hardening of internally oxidized Ag/CdO 90/10 by cold workingAgCdO9010">[[File:Strain hardening of internally oxidized AgCdO9010.jpg|rightleft|thumb|<caption>Strain hardening of internally oxidized Ag/CdO 90/10 by cold working</caption>]]Fig. 2.78: Softening of internally oxidized Ag/CdO 90</10 after annealing for 1 hr after 40% cold working[[File:Softening of internally oxidized AgCdO9010.jpg|right|thumb|Softening of internally oxidized Ag/CdO 90/10 after annealing for 1 hr after 40% cold working]]'''Table 2.25: Physical and Mechanical Properties as well as Manufacturing Processes and Forms of Supply of Extruded Silver Cadmium Oxide (DODURIT CdO) Contact Materials'''figure>

Fig. 2.79: Strain hardening of Ag/CdO 90/10 P by cold working[[File:Strain hardening of AgCdO9010P.jpg|right|thumb|Strain hardening of Ag/CdO 90/10 P by cold working]]Fig. 2.80<figure id="fig: Softening of Ag/CdO 90/10 P after annealing for 1 hr after 40% cold workinginternally oxidized AgCdO9010">[[File:Softening of AgCdO9010P after annealinginternally oxidized AgCdO9010.jpg|rightleft|thumb|<caption>Softening of internally oxidized (i.o.) Ag/CdO 90/10 P after annealing for 1 hr after 40% cold working]]Fig. 2.81: Strain hardening of Ag</CdO 88/12 WP[[File:Strain hardening of AgCdO8812.jpg|right|thumb|Strain hardening of Ag/CdO 88/12 WP]]Fig. 2.82: Softening of Ag/CdO 88/12WP after annealing for 1 hr after different degrees of cold working[[File:Softening of AgCdO8812WP after annealing.jpg|right|thumb|Softening of Ag/CdO 88/12WP after annealing for 1 hr after different degrees of cold working]]Fig. 2.83: Micro structure of Ag/CdO 90/10 i.o. a) close to surface b) in center area[[File:Micro structure of AgCdO9010.jpg|right|thumb|Micro structure of Ag/CdO 90/10 i.o. a) close to surface b) in center area]]Fig. 2.84: Micro structure of Ag/CdO 90/10 P: a) perpendicular to extrusion direction b) parallel to extrusion direction[[File:Micro structure of AgCdO9010P.jpg|right|thumb|Micro structure of Ag/CdO 90/10 P: a) perpendicular to extrusion direction b) parallel to extrusion direction]]Fig. 2.85: Micro structure of Ag/CdO 90/10 ZH: 1) Ag/CdO layer 2) AgCd backing layer[[File:Micro structure of AgCdO9010ZH.jpg|right|thumb|Micro structure of Ag/CdO 90/10 ZH: 1) Ag/CdO layer 2) AgCd backing layer]]Fig. 2.86: Micro structure of AgCdO 88/12 WP: a) perpendicular to extrusion direction b) parallel to extrusion direction[[File:Micro structure of AgCdO8812WP.jpg|right|thumb|Micro structure of AgCdO 88/12 WP: a) perpendicular to extrusion direction b) parallel to extrusion directioncaption>]]*Silver–tin oxide(SISTADOX)materialsOver the past years, many Ag/CdO contact materials have been replaced by Ag/SnO₂ based materials with 2-14 wt% SnO<sub>2</subfigure> because of the toxicity of Cadmium. This changeover was further favored by the fact that Ag/SnO₂ contacts quite often show improved contact and switching properties such as lower arc erosion, higher weld resistance, and a significant lower tendency towards material transfer in DC switching circuits ''(Table 2.30)''. Ag/SnO₂ materials have been optimized for a broad range of applications by other metal oxide additives and modification in the manufacturing processes that result in different metallurgical, physical and electrical properties ''(Table 2.29)''.

<figure id="fig:Strain hardening of AgCdO9010P">[[File:Strain hardening of AgCdO9010P.jpg|left|thumb|<caption>Strain hardening of powder metallurgical (p.m.) Ag/CdO 90/10 by cold working</caption>]]</figure> <figure id="fig:Softening of AgCdO9010P after annealing">[[File:Softening of AgCdO9010P after annealing.jpg|left|thumb|<caption>Softening of powder metallurgical Ag/CdO 90/10 after annealing for 1 hr after 40% cold working</caption>]]</figure> <figure id="fig:Strain hardening of AgCdO8812">[[File:Strain hardening of AgCdO8812.jpg|left|thumb|<caption>Strain hardening of powder metallurgical Ag/CdO 88/12</caption>]]</figure> <figure id="fig:Softening of AgCdO8812WP after annealing">[[File:Softening of AgCdO8812WP after annealing.jpg|left|thumb|<caption>Softening of powder metallurgical Ag/CdO 88/12 after annealing for 1 hr after different degrees of cold working</caption>]]</figure> <figure id="fig:Micro structure of AgCdO9010">[[File:Micro structure of AgCdO9010.jpg|left|thumb|<caption>Micro structure of Ag/CdO 90/10 i.o. a) close to surface b) in center area</caption>]]</figure> <figure id="fig:Micro structure of AgCdO9010P">[[File:Micro structure of AgCdO9010P.jpg|left|thumb|<caption>Micro structure of Ag/CdO 90/10 p.m.: a) perpendicular to extrusion direction b) parallel to extrusion direction</caption>]]</figure> </div><div class="clear"></div>  *'''Silver–tin oxide materials'''Over the past years, many Ag/CdO contact materials have been replaced by Ag/SnO₂ based materials with 2-14 wt% SnO₂ because of the toxicity of Cadmium. This changeover was further favored by the fact that Ag/SnO₂ contacts quite often show improved contact and switching properties such as lower arc erosion, higher weld resistance and a significant lower tendency towards material transfer in DC switching circuits (<xr id="tab:Contact and Switching Properties of Silver–Metal Oxide Materials"/>)<!--(Table 2.30)-->. Ag/SnO₂ materials have been optimized for a broad range of applications by other metal oxide additives and modification in the manufacturing processes that result in different metallurgical, physical and electrical properties (<xr id="tab:tab2.28"/><!--(Tab. 2.28)--> and <xr id="tab:tab2.29"/>)<!--(Table 2.29)-->. Manufacturing of Ag/SnO₂ by ''internal oxidation'' is possible in principle, but during heat treatment of alloys containing > 5 wt% of tin in oxygen, dense oxide layers formed on the surface of the material prohibit the further diffusion of oxygen into the bulk of the material. By adding Indium or Bismuth to the alloy , the internal oxidation is possible and results in materials that typically are rather hard and brittle and may show somewhat elevated contact resistance and is limited to applications in relays. To make a ductile material with fine oxide dispersion (SISTADOX TOS F) ''(Fig. 2.114)'' it is necessary to use special process variations in oxidation and extrusion which lead to materials with improved properties in relays. Adding a brazable fine silver layer to such materials results in a semifinished material , suitable for the manufacture as smaller weld profiles(SISTADOX <xr id="fig:Micro structure of Ag SnO2 92 8 WTOS F"/>) ''<!--(Fig. 2.116)''-->. Because of their resistance to material transfer and low arc erosion , these materials find for example a broaderapplication in automotive relays ''(<xr id="tab:Application Examples of Silver–Metal Oxide Materials"/>)<!--(Table 2.31)''-->.

additives improve the wettability of the oxide particles and increase the viscosity of the Ag melt. They also provide additional benefits to the mechanical and arcing contact properties of materials in this group ''(<xr id="tab:tab2.26"/>)<!--(Table 2.26)-->. <figtable id="tab:tab2.26"><caption>'''<!--Table 2.26:--> Physical and Mechanical Properties as well as Manufacturing Processes and Forms of Supply of Extruded Silver-Tin Oxide Contact Materials'''</caption>

In the manufacture the initial powder mixes different processes are applied which provide specific advantages of the resulting materials in respect to their contact properties ''{| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material !Silver Content<br />[wt%]!Additives!Theoretical<br />Density<br />[g/cm³]!Electrical<br />Conductivity<br />[MS/m]!Vickers<br />Hardness<br />[HV0,1]!Tensile<br />Strength<br />[MPa]!Elongation (Figssoft annealed)<br />A[%]min. !Manufacturing<br />Process!Form of Supply|-|Ag/SnO₂ 98/2 SPW|97 - 99|WO₃|10,4|59 ± 2|57 ± 15|215|35|Powder Metallurgy|1|-|Ag/SnO₂ 92/8 SPW|91 - 93|WO₃|10,1|51 ± 2|62 ± 15|255|25|Powder Metallurgy|1|-|Ag/SnO₂ 90/10 SPW|89 - 91|WO₃|10|47 ± 5||250|25|Powder Metallurgy|1|-|Ag/SnO₂ 88/12 SPW|87 - 89|WO₃|9.9|46 ± 5|67 ± 15|270|20|Powder Metallurgy|1|-|Ag/SnO₂ 92/8 SPW4|91 - 93|WO₃|10,1|51 ± 2|62 ± 15|255|25|Powder Metallurgy|1,2|-|Ag/SnO₂ 90/10 SPW4|89 - 91|WO₃|10|||||Powder Metallurgy|1,2|-|Ag/SnO₂ 88/12 SPW4<br />|87 – - 89|WO₃|9,8|46 ± 5|80 ± 10|||Powder Metallurgy|1,2|-|Ag/SnO₂ 88/12 SPW6|87 - 89|MoO₃|9.119)''8|42 ± 5|70 ± 10|||Powder Metallurgy|2|-|Ag/SnO₂ 97/3 SPW7|96 - 98|Bi₂O₃ and WO₃||||||Powder Metallurgy|2|-|Ag/SnO₂ 90/10 SPW7|89 - 91|Bi₂O₃ and WO₃|9,9|||||Powder Metallurgy|2|-|Ag/SnO₂ 88/12 SPW7|87 - 89|Bi₂O₃ and WO₃|9. Some of them are described here as follows:8|42 ± 5|70 ± 10|||Powder Metallurgy|2|-|Ag/SnO₂ 98/2 PMT1|97 - 99|Bi₂O₃ and CuO|10,4|57 ± 2||215|35|Powder Metallurgy|1,2|-|Ag/SnO₂ 96/4 PMT1|95 - 97|Bi₂O₃ and CuO||||||Powder Metallurgy|1,2|-|Ag/SnO₂ 94/6 PMT1|93 - 95|Bi₂O₃ and CuO||||||Powder Metallurgy|1,2|-|Ag/SnO₂ 92/8 PMT1|91 - 93|Bi₂O₃ and CuO|10|50 ± 2|62 ± 15|240|25|Powder Metallurgy|1,2|-|Ag/SnO₂ 90/10 PMT1|89 - 91|Bi₂O₃ and CuO|10|48 ± 2|65 ± 15|240|25|Powder Metallurgy|1,2|-|Ag/SnO₂ 88/12 PMT1|87 - 89|Bi₂O₃ and CuO|9,9|46 ± 5||260|20|Powder Metallurgy|1,2|-|Ag/SnO₂ 90/10 PE|89 - 91|Bi₂O₃ and CuO|9,8|48 ± 2|55 - 100|230 - 330|28|Powder Metallurgy|1|-|Ag/SnO₂ 88/12 PE|87 - 89|Bi₂O₃ and CuO|9,7|46 ± 5|60 - 106|235 - 330|25|Powder Metallurgy|1|-|Ag/SnO₂ 88/12 PMT2|87 - 89|CuO|9,9||90 ± 10|||Powder Metallurgy|1,2|-|Ag/SnO₂ 86/14 PMT3|85 - 87|Bi₂O₃ and CuO|9,8||95 ± 10||:'''a) |Powder blending from single component powders''' Metallurgy|2|-|Ag/SnO<brsub>2</sub> 94/6 LC1|93 - 95|Bi₂O₃ and In₂O₃|9,8|45 ± 5|55 ± 10|||Powder Metallurgy|2|-|Ag/SnO₂ 90/10 POX1|89 - 91|In₂O₃|9,9|50 ± 5|85 ± 15|310|25|Internal Oxidation|1,2|-|Ag/SnO₂ 90/10 POX1|87 - 89|In₂O₃|9,8|48 ± 5|90 ± 15|325|25|Internal Oxidation|1,2|-|Ag/SnO₂ 90/10 POX1|85 - 87 |In this common process all components including additives that are part of the powder mix are blended as single powders. The blending is usually performed in the dry stage in blenders of different design.₂O₃|9,6|45 ± 5|95 ± 15|330|20|Internal Oxidation|1,2|-|}</figtable>

:'''b) Powder blending on the basis of doped powders''' <br> For incorporation of additive oxides in the SnO_{1 = Wires, Rods, Contact rivets, 2} powder the reactive spray process (RSV) has shown advantages. This process starts with a waterbased solution of the tin and other metal compounds. This solution is nebulized under high pressure and temperature in a reactor chamber. Through the rapid evaporation of the water each small droplet is converted into a salt crystal and from there by oxidation into a tin oxide particle in which the additive metals are distributed evenly as oxides. The so created doped AgSnO2 powder is then mechanically mixed with silver powder.= Strips, Profiles, Contact tips

 In the manufacture for the initial powder mixes, different processes are applied which provide specific advantages of the resulting materials in respect to their contact properties <!--[[#figures|(Figs. 43 – 75)]]-->. Some of them are described here as follows::'''a) Powder blending from single component powders''' <br> In this common process all components, including additives that are part of the powder mix, are blended as single powders. The blending is usually performed in the dry stage in blenders of different design. :'''b) Powder blending on the basis of doped powders''' <br> For incorporation of additive oxides in the SnO₂ powder, the reactive spray process has shown advantages. This process starts with a waterbased solution of the tin and other metal compounds. This solution is nebulized under high pressure and temperature in a reactor chamber. Through the rapid evaporation of the water, each small droplet is converted into a salt crystal and from there gets transformed by oxidation into a tin oxide particle in which the additive metals are distributed evenly as oxides. The so created doped AgSnO₂ powder is then mechanically mixed with silver powder. :'''c) Powder blending based on coated oxide powders''' <br> In this process , tin oxide powder is blended with lower meting melting additive oxides such as for example Ag₂ MoO₄ and then heat treated. The SnO₂ particles are coated in this step with a thin layer of the additive oxide.

:'''e) Powder blending based on chemically precipitated compound powders''' <br> A silver salt solution is added to a suspension of for example SnO₂ together with a precipitation agent. In a chemical reaction , silver and silver oxide respectively are precipitated around the additive metal oxide particles , who act as crystallization sites. Further chemical treatment then reduces the silver oxide with the resulting precipitated powder , being a mix of Ag and SnO₂.

Further processing of these differently produced powders follows the conventional processes of pressing, sintering and hot extrusion to wires and strips. From these contact parts such as , contact rivets and tips are manufactured. To obtain a brazable backing , the same processes as used for Ag/CdO are applied. As for Ag/CdO, larger contact tips can also be manufactured more economically using the press-sinter-repress (PSR) process ''(<xr id="tab:Physical Properties of Powder Metallurgical Silver-Metal Oxide Materials with Fine Silver Backing Produced by the Press-Sinter-Repress Process"/>)<!--(Table 2.27)-->.''<div id="figures">

Fig. 2.87: Strain hardening of Ag/SnO<subdiv class="multiple-images">2</sub> 92/8 PE by cold working[[Filefigure id="fig:Strain hardening of AgSNO2 92 8 PE.jpg|right|thumb|Strain hardening of Ag/SnO₂ 92/8 PE by cold working]]Fig. 2.88: Softening of Ag/SnO_{2</sub"> 92/8 PE after annealing for 1 hr after 40% cold working[[File:Softening Strain hardening of AgSnO2 AgSNO2 92 8 PE.jpg|right|thumb|Softening of Ag/SnO₂ 92/8 PE after annealing for 1 hr after 40% cold working]]'''Table 2.26: Physical and Mechanical Properties as well as Manufacturing Processes andForms of Supply of Extruded Silver-Tin Oxide (SISTADOX) Contact Materials'''Fig. 2.89: Strain hardening of Ag/SnO₂ 88/12 PE by cold working[[File:Strain hardening of Ag SnO2 88 12 PE.jpg|right|thumb|Strain hardening of Ag/SnO₂ 88/12 PE by cold working]]Fig. 2.90: Softening of Ag/SnO₂ 88/12 PE after annealing for 1 hr after 40% cold working[[File:Softening of Ag SnO2 88 12 PE after annealing.jpg|rightleft|thumb|Softening of Ag/SnO<subcaption>2} 88/12 PE after annealing for 1 hr after 40% cold working]]Fig. 2.91: Strain hardening of oxidized Ag/SnO₂ 88/12 PW4 by cold working[[File:Strain hardening of oxidized AgSnO2 88 12 PW4.jpg|right|thumb|Strain hardening of oxidized Ag/SnO₂ 88/12 PW4 by cold working]]Fig. 2.92: Softening of Ag/SnO₂ 88/12 PW4 after annealing for 1 hr after 30% cold working[[File:Softening of Ag SnO2 88 12 PW4 after annealing.jpg|right|thumb|Softening of Ag/SnO₂ 88/12 PW4 after annealing for 1 hr after 30% cold working]]Fig. 2.93: Strain hardening of Ag/SnO₂ 98/2 PX by cold working[[File:Strain hardening of Ag SnO2 98 2 PX.jpg|right|thumb|Strain hardening of Ag/SnO₂ 98/2 PX by cold working]]Fig. 2.94: Softening of Ag/SnO₂ 98/2 PX after annealing for 1 hr after 80% cold working[[File:Softening of Ag SnO2 98 2 PX after annealing.jpg|right|thumb|Softening of Ag/SnO₂ 98/2 PX after annealing for 1 hr after 80% cold working]]Fig 2.95: Strain hardening of Ag/SnO₂ 92/8 PX PE by cold working[[File:Strain hardening of Ag SnO2 92 8 PX.jpg|right|thumb|Strain hardening of Ag/SnO<sub>2</subcaption> 92/8 PX by cold working]]Fig. 2.96: Softening of Ag/SnO<sub>2</subfigure> 92/8 PX after annealing for 1 hr after 40% cold working[[File:Softening of Ag SnO2 92 8 PX after annealing.jpg|right|thumb|Softening of Ag/SnO₂ 92/8 PX after annealing for 1 hr after 40% cold working]]Fig. 2.97: Strain hardening of internally oxidized Ag/SnO₂ 88/12 TOS F by cold working

Fig<figure id="fig:Softening of AgSnO2 92 8 PE"> [[File:Softening of AgSnO2 92 8 PE. 2.98: jpg|left|thumb|<caption>Softening of Ag/SnO₂ 8892/12 TOS F 8 PE after annealing for 1 hr after 3040% cold working</caption>]]</figure>

Fig<figure id="fig:Strain hardening of Ag SnO2 88 12 PE"> [[File:Strain hardening of Ag SnO2 88 12 PE. 2.99: jpg|left|thumb|<caption>Strain hardening of internally oxidized Ag/SnO₂ 88/12P 12 PE by cold working</caption>]]</figure>

Fig. 2.100<figure id="fig:Softening of Ag SnO2 88 12 PE after annealing"> [[File:Softening of Ag SnO2 88 12 PE after annealing.jpg|left|thumb|<caption>Softening ofAg/SnO₂ 88/12P12 PE after annealing for 1 hr after40% cold working</caption>]]</figure>

Fig. 2.101<figure id="fig:Strain hardening of oxidized AgSnO2 88 12 PW4"> [[File:Strain hardening of oxidized AgSnO2 88 12 PW4.jpg|left|thumb|<caption>Strain hardening ofoxidized Ag/SnO₂ 88/12 WPCPW4 by cold working</caption>]]</figure>

Fig. 2.102<figure id="fig:Softening of Ag SnO2 88 12 PW4 after annealing"> [[File:Softening of Ag SnO2 88 12 PW4 after annealing.jpg|left|thumb|<caption>Softening of Ag/SnO₂ 88/12 WPC PW4 after annealingfor 1 hr after different degrees of 30% cold working</caption>]]</figure>

Fig. 2.103<figure id="fig:Strain hardening of internally oxidized Ag SnO2 88 12 TOS F"> [[File:Strain hardening of internally oxidized Ag SnO2 88 12 TOS F.jpg|left|thumb|<caption>Strain hardening ofinternally oxidized Ag/SnO₂ 8688/14 WPC12 TOS F by cold working</caption>]]</figure>

Fig. 2.104<figure id="fig:Softening of Ag SnO2 88 12 TOS F after annealing"> [[File:Softening of Ag SnO2 88 12 TOS F after annealing.jpg|left|thumb|<caption>Softening of Ag/SnO₂ 8688/14 WPC 12 TOS F after annealingfor 1 hr after different degrees of 30% cold working</caption>]]</figure>

Fig. 2.105<figure id="fig:Strain hardening of internally oxidized Ag SnO2 88 12P"> [[File:Strain hardening of internally oxidized Ag SnO2 88 12P.jpg|left|thumb|<caption>Strain hardening ofinternally oxidized Ag/SnO₂ 88/12 WPD12P by cold working</caption>]]</figure>

Fig. 2.106<figure id="fig:Softening of Ag SnO2 88 12P after annealing"> [[File:Softening of Ag SnO2 88 12P after annealing.jpg|left|thumb|<caption>Softening of Ag/SnO₂ 88/12 WPD SP afterannealing for 1 hr after different degreesof 40% cold working</caption>]]</figure>

Fig. 2.108<figure id="fig:Strain hardening of Ag SnO2 88 12 WPD"> Softening [[File:Strain hardening of Ag SnO2 88 12 WPD.jpg|left|thumb|<caption>Strain hardening of Ag/SnO₂ 88/12 WPX afterannealing for 1 hr after different degreesof WPD by cold working</caption>]]</figure>

Fig. 2.107<figure id="fig:Softening of Ag SnO2 88 12 WPD after annealing"> Strain hardening [[File:Softening of Ag SnO2 88 12 WPD after annealing.jpg|left|thumb|<caption>Softening ofAg/SnO₂ 88/12 WPXby WPD after annealing for 1 hr after different degrees of cold working</caption>]]</figure>

Fig<figure id="fig:Micro structure of Ag SnO2 92 8 PE"> [[File:Micro structure of Ag SnO2 92 8 PE. 2.109: jpg|left|thumb|<caption>Micro structure of Ag/SnO₂ 92/8 PE: a) perpendicular to extrusion directionb) parallel to extrusion direction</caption>]]</figure>

Fig<figure id="fig:Micro structure of Ag SnO2 88 12 PE"> [[File:Micro structure of Ag SnO2 88 12 PE. 2.110: jpg|left|thumb|<caption>Micro structure of Ag/SnO₂ 88/12 PE: a) perpendicular to extrusion directionb) parallel to extrusion direction</caption>]]</figure>

Fig<figure id="fig:Micro structure of Ag SnO2 88 12 PW"> [[File:Micro structure of Ag SnO2 88 12 PW. 2.111: jpg|left|thumb|<caption>Micro structure of Ag/SnO₂ 88/12 PWSPW: a) perpendicular to extrusion directionb) parallel to extrusion direction</caption>]]</figure>

Fig<figure id="fig:Micro structure of Ag SnO2 88 12 TOS F"> [[File:Micro structure of Ag SnO2 88 12 TOS F. 2.112: jpg|left|thumb|<caption>Micro structure of Ag/SnO₂ 9888/2 PX12 TOS F: a) perpendicular to extrusion directionb) parallel to extrusion direction</caption>]]</figure>

Fig<figure id="fig:Micro structure of Ag SnO2 92 8 WTOS F"> [[File:Micro structure of Ag SnO2 92 8 WTOS F. 2.113: jpg|left|thumb|<caption>Micro structure of Ag/SnO₂ 92/8 PXWTOS F: a) perpendicular to extrusion directionb) parallel to extrusion direction,1) AgSnO2 contact layer, 2) Ag backing layer</caption>]]</figure>

Fig<figure id="fig:Micro structure of Ag SnO2 88 12 WPD"> [[File:Micro structure of Ag SnO2 88 12 WPD. 2.114: jpg|left|thumb|<caption>Micro structure of Ag/SnO₂ 88/12 TOS FWPD: a) perpendicular parallel to extrusion direction1) AgSnO2 contact layer, 2) Ag backing layer</caption>]]b) parallel to extrusion direction</figure>

Fig. 2.115: Micro structure of Ag/SnO₂ 86/14 WPC: a) perpendicular to extrusion directionb) parallel to extrusion direction, 1) AgSnO<subdiv class="clear">2</subdiv> contact layer, 2) Ag backing layer

Fig. <figtable id="tab:Physical Properties of Powder Metallurgical Silver-Metal Oxide Materials with Fine Silver Backing Produced by the Press-Sinter-Repress Process"><caption>'''<!--Table 2.11727: Micro structure -->Physical Properties ofPowder Metallurgical Silver-Metal Oxide Materials with Fine Silver Backing Produced by the Press-Sinter-Repress Process'''</caption><table class="twocolortable"><tr><th rowspan="2"><p class="s11">Material</p><p class="s11"></p></th><th rowspan="2"><p class="s11">Additives</p></th><th rowspan="2"><p class="s11">Density</p><p class="s11">[ g/cm³]</p></th><th rowspan="2"><p class="s11">Electrical</p><p class="s11">Resistivity</p><p class="s11">[µ<span class="s14">S ·</span>cm]</p></th><th colspan="2"><p class="s11">Electrical</p><p class="s11">Conductivity</p></th><th rowspan="2"><p class="s11">Vickers</p><p class="s11">Hardness</p><p class="s11">HV 10.</p></th></tr>Ag<tr><th><p class="s11">[%IACS]</p></th><th><p>[MS/m]</p></th></tr><tr><td><p class="s11">AgCdO 90/10</p><p class="s11"></p></td><td/><td><p class="s11">10.1</p></td><td><p class="s11">2.08</p></td><td><p class="s12">83</p></td><td><p class="s12">48</p></td><td><p class="s11">60</p></td></tr><tr><td><p class="s11">AgCdO 85/15 </p></td><td/><td><p class="s11">9.9</p></td><td><p class="s11">2.27</p></td><td><p class="s12">76</p></td><td><p class="s12">44</p></td><td><p class="s11">65</p></td></tr><tr><td><p class="s11">AgSnO₂ 90/10</p></td><td><p class="s11">CuO and</p><p class="s11">Bi₂ O₃</p></td><td><p class="s11">9.8</p></td><td><p class="s11">2.22</p></td><td><p class="s12">78</p></td><td><p class="s12">45</SnOp></td><td><p class="s11">55</p></td></tr><tr><td><p class="s11">AgSnO₂ 88/12 WPD: parallel to extrusion direction1) AgSnO</p></td><td><p class="s11">CuO and</p><p class="s11">Bi₂ O₃</p></td><td><p class="s11">9.6</p></td><td><p class="s11">2.63</p></td><td><p class="s12">66</p></td><td><p class="s12">38</p></td><td><p class="s11">60</p></td></tr></table>Form of Support: formed parts, stamped parts, contact layer, 2) Ag backing layertips</figtable>

Fig*'''Silver–zinc oxide materials'''Silver zinc oxide contact materials with mostly 6 - 10 wt% oxide content, including other small metal oxides, are produced exclusively by powder metallurgy [[#figures1|(Figs. 58 – 63)]]<!--(Table 2.118: Micro structure of28)-->. Adding WO₃ or Ag₂WO₄ in the process - as described in the preceding chapter on Ag/SnO₂ 88- has proven most effective for applications in AC relays, wiring devices, and appliance controls. Just like with the other Ag metal oxide materials, semi-finished materials in strip and wire form are used to manufacture contact tips and rivets. Because of their high resistance against welding and arc erosion Ag/12 WPX:parallel ZnO materials present an economic alternative to extrusion direction1) AgSnOCd free Ag-tin oxide contact materials (<subxr id="tab:Contact and Switching Properties of Silver–Metal Oxide Materials"/><!--(Tab. 2.30)--> and <xr id="tab:Application Examples of Silver–Metal Oxide Materials"/sub> contact layer, )<!--(Tab. 2.31) Ag backing layer-->.

<figtable id="tab:tab2.28"><caption>'''<!--Table 2.2728: --> Physical and Mechanical Properties as well as Manufacturing Processes and Forms of Powder Metallurgical Supply of Extruded Silver-Metal Zinc Oxide Materialswith Fine Silver Backing Produced by the Press-Sinter-Repress ProcessContact'''</caption>

*'''Silver–zinc oxide (DODURIT ZnO) materials'''{| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material !Silver zinc oxide (DODURIT ZnO) contact materials with mostly 6 Content<br />[wt%]!Additives!Density<br />[g/cm³]!Electrical<br />Resistivity<br />[μΩ·cm]!colspan="2" style="text- 10 wtalign:center"|Electrical<br />Conductivity<br />[% oxideIACS] [MS/m]content including other small metal oxides are produced exclusively by powder!Vickers<br />Hardness<br />Hv1!Tensile<br />Strength<br />[MPa]metallurgy ''!Elongation<br />(Figssoft annealed)<br />A[%]min. 2!Manufacturing<br />Process!Form of<br />Supply|-|Ag/ZnO 92/8P<br />|91 - 93||9.120 – 8|2.12522|78|45|60 - 95|220 - 350|25|Powder Metallurgy<br />a)'' ''(Table 2indiv.28)''. Adding powders|1|-|Ag/ZnO 92/8PW25<br />|91 - 93|Ag₂WO₄ in the process b|9.6|2.08|83|48|65 - 105|230 - 340|25|Powder Metallurgy<br />c)coatedas described in the preceding chapter on |1|-|Ag/SnOZnO 90/10PW25<br />|89 - 91|Ag₂ has proven most effectiveWO₄for applications in AC relays, wiring devices, and appliance controls|9. Just like6|2.17|79|46|65 - 100|230 - 350|20|Powder Metallurgy<br />c) coated|1|-|Ag/ZnO 92/8WP<br />|91 - 93||9.8|2.0|86|50|60 - 95|||Powder Metallurgy<br />with the other Ag metal oxide materials, semibacking a) individ.|2|-finished materials in strip and wireform are used to manufacture contact tips and rivets|Ag/ZnO 92/8WPW25<br />|91 - 93|Ag₂WO₄|9.6|2.08|83|48|65 - 105|||Powder Metallurgy<br />c) coatedBecause of their high resistance against welding and arc erosion |2|-|Ag/ZnO90/10WPW25<br />materials present an economic alternative to Cd free Ag|89 -tin oxide contact91materials ''(Tables |Ag₂WO₄|9.30 and 6|2.317|79|46|65 - 110|||Powder Metallurgy<br />c)''.coated|2|}</figtable>

Table 1 = Wires, Rods, Contact rivets, 2.28: Physical and Mechanical Properties as well as Manufacturing Processes andForms of Supply of Extruded Silver-Zinc Oxide (DODURIT ZnO) = Strips, Profiles, Contacttips

Fig<div class="multiple-images"><figure id="fig:Strain hardening of Ag ZnO 92 8 PW25"> [[File:Strain hardening of Ag ZnO 92 8 PW25. 2.121: Softening jpg|left|thumb|<caption>Strain hardening of Ag/ZnO 92/8 PW25after annealing for 1 hr after 30% by cold working</caption>]]</figure>

Fig. 2.122<figure id="fig: Strain hardening Softening ofAg ZnO 92 8 PW25"> [[File:Softening of Ag ZnO 92 8 PW25.jpg|left|thumb|<caption>Softening of Ag/ZnO 92/8 WPW25by PW25 after annealing for 1 hr after 30% cold working</caption>]]</figure>

Fig. 2.123<figure id="fig: Softening Strain hardening ofAg ZnO 92 8 WPW25"> [[File:Strain hardening of Ag ZnO 92 8 WPW25.jpg|left|thumb|<caption>Strain hardening of Ag/ZnO 92/8 WPW25 after annealing for1hr after different degrees of by cold working</caption>]]</figure>

Fig<figure id="fig:Softening of Ag ZnO 92 8 WPW25"> [[File:Softening of Ag ZnO 92 8 WPW25. 2.115: Micro structure jpg|left|thumb|<caption>Softening of Ag/ZnO 92/8 Pw25: a) perpendicular to extrusion directionWPW25 after annealing for 1hr after different degrees of cold working</caption>]]b) parallel to extrusion direction</figure>

Fig<figure id="fig:Micro structure of Ag ZnO 92 8 PW25"> [[File:Micro structure of Ag ZnO 92 8 Pw25. 2.116: jpg|left|thumb|<caption>Micro structure of Ag/ZnO 92/8 WPW25PW25:a) perpendicular to extrusion directionb) parallel to extrusion direction, 1) Ag</caption>]]</ZnO contact layer, 2) Ag backing layerfigure>

Table 2<figure id="fig:Micro structure of Ag ZnO 92 8 WPW25"> [[File:Micro structure of Ag ZnO 92 8 WPW25.29jpg|right|thumb|<caption>Micro structure of Ag/ZnO 92/8 WPW25: Optimizing of Silver–Tin Oxide Materials Regarding their Switchinga) perpendicular to extrusion direction b) parallel to extrusion direction, 1) Ag/ZnO contact layer, 2) Ag backing layer</caption>]]</figure></div>Properties and Forming Behavior<div class="clear"></div>

<figtable id="tab:tab2.29"><caption>'''<!--Table 2.3129: Application Examples -->Optimizing of Silver–Metal Silver–Tin Oxide MaterialsRegarding their Switching Properties and Forming Behavior'''</caption><table class="twocolortable"><tr><th><p class="s12">Material/</p><p class="s12">Material Group</p></th><th><p class="s12">Special Properties<th colspan="2"></p></th></tr><tr><td><p class="s12">Ag/SnO₂ PE</p></td><td><p class="s12">Especially suitable for automotive relays</p><p class="s12">(lamp loads)</p></td><td><p class="s12">Good formability (contact rivets)</p></td></tr><tr><td><p class="s12">Ag/SnO₂ TOS F</p></td><td><p class="s12">Especially suited for high inductive</p><p class="s12">DC loads</p></td><td><p class="s12">Very good formability (contact rivets)</p></td></tr><tr><td><p class="s12">Ag/SnO₂ WPD</p></td><td><p class="s12">Especially suited for severe loads (AC-4)</p><p class="s12">and high switching currents</p></td><td/></tr><tr><td><p class="s12">Ag/SnO₂ W TOS F</p></td><td><p class="s12">Especially suitable for high inductive DC</p><p class="s12">loads</p></td><td/></tr></table></figtable>

The extrusion <figtable id="tab:Contact and Switching Properties of sintered billets is now the dominant manufacturing method forSilver–Metal Oxide Materials">semi-finished AgC materials <caption>'''(Figs. <!--Table 2.126 – 2.129)''. The hot extrusion processresults in a high density material with graphite particles stretched 30:-->Contact and oriented inthe extrusion direction Switching Properties of Silver–Metal Oxide Materials''(Figs. 2.130 – 2.133)''. Depending on the extrusionmethod in either rod or strip form the graphite particles can be oriented in thefinished contact tips perpendicular (GRAPHOR) or parallel (GRAPHOR D) to theswitching contact surface ''(Figs. 2.131 and 2.132)''.</caption>

Since {| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material!Properties|-|Ag/SnO₂<br />|Environmentally friendly materials,<br />Very high resistance against welding during current-on-switching,<br />Weld resistance increases with higher oxide contents,<br />Low and stable contact resistance over the graphite particles in life of the Ag matrix device and good<br />temperature rise properties through use of special additives,<br />High arc erosion resistance and contact life,<br />Very low and flat material transfer during DC load switching,<br />Good arc moving and very good arc extinguishing properties|-|Ag/C ZnO<br />|Environmentally friendly materials prevent contacttips from directly being welded or brazed, a graphite free bottom layer is<br />required. This is achieved by either burning out High resistance against welding during current-on-switching<br />(de-graphitizingcapacitor contactors) the graphite,<br />Low and stable contact resistance through special oxide additives,<br />Very high arc erosion resistance at high switching currents,<br />Less favorable than Ag/SnO₂ for electrical life and material transfer,<br />selectively on one side of the tips or by compound extrusion of a With Ag<sub>2</C billetsub>WO₄ additive especially suitable for AC relays|}covered with a fine silver shell.</figtable>

A disadvantage <figtable id="tab:Application Examples of the Silver–Metal Oxide Materials"><caption>'''<!--Table 2.31:-->Application Examples of Silver–Metal Oxide Materials'''</caption><table class="twocolortable"><tr><th><p class="s12">Material</p></th><th><p class="s12">Application Examples</p></th></tr><tr><td><p class="s12">Ag/SnO₂<span class="s48"></span></p></td><td><p class="s12">Micro switches, Network relays, Automotive relays, Appliance switches,</p><p class="s12">Main switches, contactors, Fault current protection relays (paired against</p><p class="s12">Ag/C materials is their rather high erosion rate. In materials), (Main) Power switches</p></td></tr><tr><td><p class="s12">Ag/ZnO</p></td><td><p class="s12">Wiring devices, AC relays, Appliance switches, Motor-protective circuit</p><p class="s12">breakers (paired with parallel graphite orientation this can be improved if part of the graphite isincorporated into the material in the form of fibers (GRAPHOR DFAg/Ni or Ag/C), ''Fault current circuit breakers paired againct Ag/C, (Fig. 2.133Main)''.Power switches</p></td></tr></table>The weld resistance is determined by the total content of graphite particles.</figtable>

====Silver–Graphite Materials====Ag/C tips contact materials are usually produced by powder metallurgy with vertical graphite particle orientation are produced in a specificsequencecontents of 2 – 6 wt% (<xr id="tab: Extrusion to rods, cutting of double thickness tips, burning out ofgraphite to a controlled layer thickness, and a second cutting to single tipstab2.Such contact tips are especially well suited for applications which require both,a high weld resistance and a sufficiently high arc erosion resistance ''32"/>)<!--(Table 2.3332)''-->.For attachment The earlier typical manufacturing process of Ag/C single pressed tips welding by pressing - sintering - repressing (PSR) has been replaced in Europe for quite some time by extrusion. In North America and brazing techniques are appliedsome other regions however the PSR process is still used to some extend mainly for cost reasons.

welding The extrusion of sintered billets is now the actual dominant manufacturing method for semi-finished AgC materials<!--[[#figures3|(Figs. 64 – 67)]]<!--(Figs. 2.126 – 2.129)-->. The hot extrusion process depends on the results in a high density material's graphite orientation. ForAg/C tips with vertical graphite orientation particles stretched and oriented in the contacts are assembled withsingle tipsextrusion direction [[#figures4|(Figs. 68 – 71)]]<!--(Figs. 2.130 – 2.133)-->. For parallel orientation a more economical attachment starting withcontact material Depending on the extrusion method in either rod or strip or profile tape form is used , the graphite particles can be oriented in integrated stamping andwelding operations with the tape fed into the weld station, cut off to tip form andthen welded finished contact tips perpendicular or parallel to the carrier material before forming the final switching contact assemblypartsurface (<xr id="fig:Micro structure of Ag C 95 5"/><!--(Fig. 2. For special low energy welding the 131)--> and <xr id="fig:Micro structure of Ag/C profile tapes GRAPHOR 96 4 D and DFcan be pre"/>)<!--(Fig. 2.132)--coated with a thin layer of high temperature brazing alloys such asCuAgP>.

In a rather limited way, Since the graphite particles in the Ag matrix of Ag/C with 2 – 3 wt% materials prevent contact tips from directly being welded or brazed, a graphite can be produced in wireform and headed into contact rivet shape with low head deformation ratiosfree bottom layer is required. This is achieved by burning out (de-graphitizing) the graphite selectively on one side of the tips.

The main applications for Ag/C contact materials are protective switching devices suchas miniature molded case circuit breakers, motor-protective circuit breakers,and fault current circuit breakers, where during short circuit failures highestexhibit on the one hand an extremely high resistance against to contact welding is required ''(Table 2.34)''. For higher currents but on the other have a lowarc erosion resistance of Ag/C . This is compensated caused by asymmetrical pairing the reaction of graphite withmore erosion resistant the oxygen in the surrounding atmosphere at the high temperatures created by the arcing. The weld resistance is especially high for materials such as Ag/Ni and Ag/Wwith the graphite particle orientation parallel to the arcing contact surface. Since the contact surface after arcing consists of pure silver, the contact resistance stays consistantly low during the electrical life of the contact parts.

FigA disadvantage of the Ag/C materials is their rather high erosion rate. 2.126In materials with parallel graphite orientation this can be improved, if a part of the graphite is incorporated into the material (Ag/C DF) in the form of fibers (<xr id="fig:Strain hardeningMicro structure of Ag/C 96DF"/4 D>)<!--(Fig. 2.133)-->. The weld resistance is determined by cold workingthe total content of graphite particles.

FigAg/C tips with vertical graphite particle orientation are produced in a specific sequence: Extrusion to rods, cutting of double thickness tips, burning out of graphite to a controlled layer thickness, and a second cutting to single tips. Such contact tips are especially well suited for applications which require both, a high weld resistance and a sufficiently high arc erosion resistance (<xr id="tab:tab2.33"/>)<!--(Table 2.127:Softening 33)-->. For attachment of Ag/C 96/4 D afterannealingtips welding and brazing techniques are applied.

FigWelding the actual process depends on the material's graphite orientation. 2For Ag/C tips with vertical graphite orientation the contacts are assembled with single tips.128: Strain hardeningof For parallel orientation a more economical attachment starting with contact material in strip or profile tape form is used in integrated stamping and welding operations with the tape fed into the weld station, cut off to tip form and then welded to the carrier material before forming the final contact assembly part. For special low energy welding, the Ag/C DF by cold workingprofile tapes can be pre-coated with a thin layer of high temperature brazing alloys such as CuAgP.

Fig. 2.129: Softeningof In a rather limited way, Ag/C DF after annealingwith 2 – 3 wt% graphite can be produced in wire form and headed into contact rivet shape with low head deformation ratios.

FigThe main applications for Ag/C materials are protective switching devices such as miniature molded case circuit breakers, motor-protective circuit breakers, and fault current circuit breakers, where during short circuit failures, highest resistance against welding is required (<xr id="tab:tab2. 34"/>)<!--(Table 2.130: Micro structure 34)-->. For higher currents the low arc erosion resistance of Ag/C 97is compensated by asymmetrical pairing with more erosion resistant materials such as Ag/3: a) perpendicular to extrusion directionb) parallel to extrusion directionNi, 1) Ag/C contact layer, 2) W and Ag backing layer/WC.

Fig. 2<div class="multiple-images"><figure id="fig:Strain hardening of Ag C 96 4 D">[[File:Strain hardening of Ag C 96 4 D.131: Micro structure jpg|left|thumb|<caption>Strain hardening of Ag/C 9596/4 by cold working</5: a) perpendicular to extrusion directioncaption>]]b) parallel to extrusion direction, 1) Ag</C contact layer, 2) Ag backing layerfigure>

Fig. 2.132<figure id="fig: Micro structure Softening of Ag/C 96/4 D"> [[File: a) perpendicular to extrusion directionb) parallel to extrusion direction, 1) Softening of Ag C 96 4 D.jpg|left|thumb|<caption>Softening of Ag/C contact layer, 2) Ag backing layer96/4 after annealing</caption>]]</figure>

Fig. 2.133<figure id="fig: Micro structure Strain hardening of Ag/C DF"> [[File: a) perpendicular to extrusion directionb) parallel to extrusion direction, 1) Strain hardening of Ag C DF.jpg|left|thumb|<caption>Strain hardening of Ag/C contact layer, 2) AgDF by cold working</Ni 90caption>]]</10 backing layerfigure>

Table 2<figure id="fig:Softening of Ag C DF after annealing"> [[File:Softening of Ag C DF after annealing.32: Physical Properties jpg|left|thumb|<caption>Softening of Silver–Graphite (GRAPHOR) Contact MaterialsAg/C DF after annealing</caption>]]</figure>

Table 2<figure id="fig:Micro structure of Ag C 97 3"> [[File:Micro structure of Ag C 97 3.33jpg|left|thumb|<caption>Micro structure of Ag/C 97/3: Contact and Switching properties of Silver–Graphite (GRAPHORa) perpendicular to extrusion direction b) parallel to extrusion direction, 1) Ag/C contact layer, 2) Contact MaterialsAg backing layer</caption>]]</figure>

Table 2.34<figure id="fig:Micro structure of Ag C 95 5"> [[File: Application Examples and Forms Micro structure of Supply Ag C 95 5.jpg|left|thumb|<caption>Micro structure of Silver–Ag/C 95/5: a) perpendicular to extrusion direction b) parallel to extrusion direction, 1) Ag/C contact layer, 2) Ag backing layer</caption>]]Graphite (GRAPHOR) Contact Materials</figure>

Pre<figure id="fig:Micro structure of Ag C 96 4 D"> [[File:Micro structure of Ag C 96 4 D.jpg|left|thumb|<caption>Micro structure of Ag/C 96/4: a) perpendicular to extrusion direction b) parallel to extrusion direction, 1) Ag/C contact layer, 2) Ag backing layer</caption>]]</figure> <figure id="fig:Micro structure of Ag C DF"> [[File:Micro structure of Ag C DF.jpg|left|thumb|<caption>Micro structure of Ag/C DF: a) perpendicular to extrusion direction b) parallel to extrusion direction, 1) Ag/C contact layer, 2) Ag/Ni 90/10 backing layer</caption>]]</figure></div><div class="clear"></div> <figtable id="tab:tab2.32"><caption>'''<!--Table 2.32:-->Physical Properties of Silver–Graphite Contact Materials'''</caption> {| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material !Silver Content<br />[wt%]!Density<br />[g/cm³]!Melting Point<br />[°C]!Electrical Resistivity<br />[μΩ·cm]!colspan="2" style="text-align:center"|Electrical<br />Conductivity<br />[% IACS] [MS/m]!Vickers-Hardnes<br />HV10<br />42 - 45|-|Ag/C 98/2|97.5 - 98.5|9.5|960|1.85 - 1.92|90 - 93|48 - 50|42 - 44|-|Ag/C 97/3|96.5 - 97.5|9.1|960|1.92 - 2.0|86 - 90|45 - 48|41 - 43|-|Ag/C 96/4|95.5 - 96.5|8.7|960|2.04 - 2.13|81 - 84|42 - 46|40 - 42|-|Ag/C 95/5|94.5 - 95.5|8.5|960|2.12 - 2.22|78 - 81|40 - 44|40 - 60|-|AgC DF<br />GRAPHOR DF[[#text-reference1|¹]]|95.7 - 96.7|8.7 - 8.9|960|2.27 - 2.50|69 - 76|40 - 44|-|}<div id="text-reference1">₁ Graphite content 3.8 wt%, Graphite particles and fibers parallel to switching surface</div></figtable>    <figtable id="tab:tab2.33"><caption>'''<!--Table 2.33:-->Contact and Switching properties of Silver–Graphite Contact Materials'''</caption><table class="twocolortable"><tr><th><p class="s12">Material</p></p></th><th><p class="s11">Properties</p></th></tr><tr><td><p class="s12">Ag/C</p></p></td><td><p class="s12">Highest resistance against welding during make operations at high currents,</p><p class="s12">High resistance against welding of closed contacts during short circuit,</p><p class="s12">Increase of weld resistance with higher graphite contents, Low contact resistance,</p><p class="s12">Low arc erosion resistance, especially during break operations, Higher arc erosion with increasing graphite contents, at the same time carbon build-up on switching chamber walls increases, silver-Production graphite with vertical orientation has better arc erosion resistance, parallel orientation has better weld resistance,</p><p class="s12">Limited arc moving properties, therefore paired with other materials,</p><p class="s12">Limited formability,</p><p class="s12">Can be welded and brazed with decarbonized backing, GRAPHOR DF is optimized for arc erosion resistance and weld resistance</p></td></tr></table></figtable>  <figtable id="tab:tab2.34"><caption>'''<!--Table 2.34:-->Application Examples and Forms of Supply of Silver– Graphite Contact Materials'''</caption><table class="twocolortable"><tr><th><p class="s12">Material</p><p class="s12"></p></th><th><p class="s12">Application Examples</p></th><th><p class="s12">Form of Supply</p></th></tr><td><p class="s12">Ag/C 98/2</p><p class="s12"></p></td><td><p class="s12">Motor circuit breakers, paired with Ag/Ni</p></td><td><p class="s12">Contact tips, brazed and welded contact parts, some contact rivets </p><p class="s12">Contact profiles (weld tapes), Contact tips, brazed and welded contact parts</p></td></tr><tr><td><p class="s12">Ag/C 97/3</p><p class="s12"></p><p class="s12">Ag/C 96/4</p><p class="s12"></p><p class="s12">Ag/C 95/5</p><p class="s12"></p><p class="s12">Ag/C DF</p></td><td><p class="s12">Circuit breakers, paired with Cu, Motor-protective circuit breakers, paired with Ag/Ni,</p><p class="s12">Fault current circuit breakers, paired with Ag/Ni, Ag/W, Ag/WC, Ag/SnO₂<span class="s45"></span>, Ag/ZnO,</p><p class="s12">(BildMain)Power switches, paired with Ag/Ni, Ag/W</p></td><td><p class="s12">Contact tips, brazed and welded contact</p><p class="s12">parts, some contact rivets with</p><p class="s12">Ag/C97/3</p></td></tr></table></figtable>