Changes

<xr id="tab:tab2.11Overview_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:tab2.12Quality_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:tab2.16Application 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:tab2.11Overview_of_the_Most_Widely_Used_Silver_Grades"><caption>'''<!--Table 2.11: -->Overview of the Most Widely Used Silver Grades'''</caption><table borderclass="1" cellspacing="0" style="border-collapse:collapsetwocolortable"><tr><tdth><p class="s12">Designation</p></tdth><tdth><p class="s12">Composition minimum Ag [wt%]</p></tdth><tdth><p class="s12">Impurities</p><p class="s12">[ppm]</p></tdth><tdth><p class="s12">Notes on Usage</p></tdth></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 alloyingpurposes</p><p class="s12">purposes</p></td></tr></table>

<figtable id="tab:tab2.12Quality_Criteria_of_Differently_Manufactured_Silver_Powders"><caption>'''<!--Table 2.12: -->Quality Criteria of Differently Manufactured Silver Powders'''</caption>

<xr id="fig:fig2.45"nowiki>*</nowiki> Fig. 2.45: Strain hardening of Ag 99.95 Manufactured by cold workingchemical precipitation <br /><nowiki>**</nowiki> Manufactured by electrolytic deposition <br /><xr id="fig:fig2.46"nowiki>***</nowiki> Fig. 2.46: Softening of Ag 99.95 after annealing for 1 hr after different degrees Manufactured by atomizing of strain hardeninga melt

<figure id="fig:fig2.45Strain hardening of Ag bei cold working">[[File:Strain hardening of Ag bei cold working.jpg|left|thumb|<caption>Strain hardening of Ag 99.95 bei - cold working</caption>]]

<figure id="fig:fig2.46Softening of Ag after annealing after different degrees">

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:tab2.14Mechanical 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 (<xr id="fig:fig2.47Influence of 1 10 atom of different alloying metals"/> <!--(Fig. 2.47) --> and <xr id="fig:fig2.48Electrical resistivity p of AgCu alloys"/> )<!--(Fig. 2.48)-->.

<xr id{| class="twocolortable" style="figtext-align:fig2left; 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.47"Coefficient of<br />the Electr.Resistance<br />[10^-3/K]!Modulus of<br />Elasticity<br /> Fig[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|2.47: Influence of 7|92|-|Ag98CuNi<br />ARGODUR 27|98|10.4|940|1.92|52|385|3.5|85|-|AgCu24.5Ni0.5|75|10 atom% of different alloying metals on the electrical resistivity of silver.0|805|2.20|45|330|2.7|92|-|Ag99.5NiMg<xr id="fig:fig2br />ARGODUR 32<br />Not heat treated|99.5|10.5|960|2.32|43|293|2.48"3|80|-|ARGODUR 32<br /> FigHeat treated|99.5|10.5|960|2. 32|43|293|2.48: Electrical resistivity p of AgCu alloys1|80|}</figtable>

<figure id="fig:fig2.47Influence of 1 10 atom of different alloying metals">

<figure id="fig:fig2.48Electrical resistivity p of AgCu alloys">

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:fig2Phase 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 (<xr id="fig:fig2Coarse grain micro structure of Ag"/><!--(Fig. 2.49"/)--> and <xr id="fig:fig2Fine grain microstructure of AgNiO"/><!--(Fig. 2.50"/)-->).

<figure id="fig:fig2.49Coarse grain micro structure of Ag">

<figure id="fig:fig2.50Fine grain microstructure of AgNiO">

<figure id="fig:fig2.51Phase diagram of silver nickel">

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:tab2.14Mechanical 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 <xr id="tab:tab2.14"/> (Table 2.14).

<figtable id="tab:tab2.14">'''Table 2.14: Mechanical Properties Increasing the Cu content further also increases the mechanical strength of Silver AgCu alloys and Silver Alloys'''<table border="1" cellspacing="0" style="borderimproves arc erosion resistance and resistance against material transfer while simultaneously the tendency to oxide formation becomes detrimental. This causes -collapse:collapse"><tr><td><p class="s12">Material/</p><p class="s12">DODUCOduring switching under arcing conditions -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 [%] minan increase in contact resistance with rising numbers of operation.</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 0In special applications, where highest mechanical strength is recommended and a reduced chemical resistance can be tolerated,15the eutectic AgCu alloy with 28 wt% of copper is used (</p><p classxr id="s12fig:Phase diagram of silver copper">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">(Fig. 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 .52)- 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">AgCu24,5Ni0also known as coin silver,5</p></td><td><p class="s12">R 300</p><p class="s12">R 600</p></td><td><p class="s12">300 has been replaced in many applications by composite silver- 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">based materials while sterling silver (AgCu7.5</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></) has never extended its important usage from decorative table></figtable>wear and jewelry to industrial applications in electrical contacts.

 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 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 <xr id="fig:fig2.52"/> (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:tab2.16"/> (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 Application Examples 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 Forms of contact springs that are exposed to high thermal and mechanical stresses in relays, and contactors Supply for aeronautic applications. '''Table 2.13: Physical Properties of Silver and Silver Alloys'''nicht gemacht! <xr id="fig:fig2.52"/> Fig. )<!--(Table 2.52: Phase diagram of silver16)-copper <xr id="fig:fig2.53"/> Fig. 2.53: Phase diagram of silver-cadmium <xr id="fig:fig2.54"/> Fig. 2.54: Strain hardening of AgCu3 by cold working <xr id="fig:fig2.55"/> Fig. 2.55: Softening of AgCu3 after annealing for 1 hr after 80% cold working <xr id="fig:fig2.56"/> Fig. 2.56: Strain hardening of AgCu5 by cold working <xr id="fig:fig2.57"/> Fig. 2.57: Softening of AgCu5 after annealing for 1 hr after 80% cold working <xr id="fig:fig2.58"/> Fig. 2.58: Strain hardening of AgCu 10 by cold working <xr id="fig:fig2.59"/> Fig. 2.59: Softening of AgCu10 after annealing for 1 hr after 80% cold working <xr id="fig:fig2.60"/> Fig. 2.60: Strain hardening of AgCu28 by cold working <xr id="fig:fig2.61"/> Fig. 2.61: Softening of AgCu28 after annealing for 1 hr after 80% cold working

<xr id="fig:fig2.62"/> Fig. 2.62: Strain hardening Dispersion hardened alloys of AgNi0silver with 0.15 5 wt% MgO and NiO (ARGODUR 32) are produced by internal oxidation. While the melt-metallurgical alloy is easy to cold working <xr id="fig:fig2-work and form, the material becomes very hard and brittle after dispersion hardening.63"/> FigCompared 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. 2.63: Softening of AgNi0.15 after annealing for 1 hr after 80% cold working <xr id="fig:fig2.64"/> Fig. 2.64: Strain hardening Because of these mechanical properties and its high electrical conductivity ARGODUR 27 by cold working <xr id="fig:fig2.65"/> Fig. 2.65: Softening 32 is mainly used in the form of ARGODUR 27 after annealing contact springs that are exposed to high thermal and mechanical stresses in relays and contactors for 1 hr after 80% cold workingaeronautic applications.

<figure id="fig:fig2.52Phase diagram of silver copper">

<figure id="fig:fig2.53"> [[File:Phase diagram Strain hardening of silver cadmium.jpg|left|thumb|<caption>Phase diagram of silver-cadmium</caption>]]</figure> <figure id="fig:fig2.54AgCu3 by cold working">

<figure id="fig:fig2.55Softening of AgCu3 after annealing">

<figure id="fig:fig2.56Strain hardening of AgCu5 by cold working">

<figure id="fig:fig2.57Softening of AgCu5 after annealing">

<figure id="fig:fig2.58Strain hardening of AgCu 10 by cold working">

<figure id="fig:fig2.59Softening of AgCu10 after annealing">

<figure id="fig:fig2.60Strain hardening of AgCu28 by cold working">

<figure id="fig:fig2.61Softening of AgCu28 after annealing">

<figure id="fig:fig2Strain hardening of AgNi0.6215 by cold working">

<figure id="fig:fig2Softening of AgNi0.6315 after annealing">

<figure id="fig:fig2.64Strain 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 id="fig:fig2.65Softening 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>]]

<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>

|Ag<br />AgNi0,.15<br />ARGODUR-Special

Cu content, compared to fine Ag higher arc erosion resistance and mechanical strength, lower tendency to materialtransfer

<figtable id="tab:tab2.16Application 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>

|Ag<br />AgNi0,.15<br />ARGODUR-Spezial<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

|Ag99, .5NiOMgO<br />ARGODUR 32

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 (<xr id="tab:Physical Properties of Silver-Palladium Alloys"/><!--(Tab 2.17) --> and <xr id="tab:tab2.18Mechanical 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:tab2.19"/> (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:tab2.20"/> (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. 

AgPd alloys are hard, arc erosion resistant, and have a lower tendency towards material transfer under DC loads (<xr id="figtab:fig2.66Contact and Switching Properties of Silver-Palladium Alloys"/> Fig. )<!--(Table 2.66: Phase diagram of silver19)--palladium>. 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="figtab:fig2.67Application Examples and Forms of Suppl for Silver-Palladium Alloys"/> Fig<!--(Table 2. 220)-->.67: Strain hardening Because of AgPd30 the high palladium price, these formerly solid contacts have been widely replaced by cold workingmulti-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.

<figure id="fig:fig2.66Phase diagram of silver palladium">

<figure id="fig:fig2.67Strain hardening of AgPd30 by cold working">

<figure id="fig:fig2.68Strain hardening of AgPd50 by cold working">

<figure id="fig:fig2.69Strain hardening of AgPd30Cu5 by cold working">

<figure id="fig:fig2.70Softening of AgPd30 AgPd50 AgPd30Cu5">

'''Table 2.17<figtable id="tab: Physical Properties of Silver-Palladium Alloys'''nicht gemacht!">

<figtable id{| class="tab:tab2.18">'''Table 2.18: Mechanical Properties of Silver-Palladium Alloys'''<table border="1" cellspacing="0twocolortable" style="bordertext-align: left; font-collapsesize:collapse12px"><tr><td><p class="s12">|-!Material!Palladium Content<br /p>[wt%]!Density<br /td><td><p class="s12">Hardness<[g/p>cm<p class="s12"sup>Condition3</psup>]!Melting Point<br /td>or Range<td><p class="s12">Tensile Strength<br /p><p class="s12">R<span class="s31">m </span>[MPa°C]!Electrical<br /p></td><td><p class="s12">Elongation AResistivity<br /p><p class="s12">[%μΩ·cm]min.!Electrical<br /p>Conductivity<br /td><td><p class="s12">Vickers Hardness<[MS/p><p class="s12">HVm]!Thermal<br /p>Conductivity<br /td><[W/tr><tr><td><p class="s12">AgPd30m·K]!Temp. Coefficient of<br /p>the Electr. Resistance<br /td>[10<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"sup>-3</psup></td><td><p class="s12">65</p><p class="s12">145</p></td></tr><tr><td><p class="s12">K]|-|AgPd30|30|10.9|1155 - 1220|14.7|6.8|60|0.4|-|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</p></td><td><p class="s12">72</p><p class="s12">165</p></td></tr><tr><td><p class="s12">|40|11.1|1225 - 1285|20.8|4.8|46|0.36|-|AgPd50</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">|50|11.2</p></td><td><p class="s12">78</p><p class="s12">185</p></td></tr><tr><td><p class="s12">|1290 - 1340|32.3|3.1|34|0.23|-|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">|60|11.4|1330 - 1385|41.7|2</p></td><td><p class="s12">85</p><p class="s12">195</p></td></tr><tr><td><p class="s12">.4|29|0.12|-|AgPd30Cu5</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</p></td><td><p class="s12">90</p><p class="s12">190</p></td></tr></table>|30|10.8|1120 - 1165|15.6|6.4|28|0.37|}

<figtable id="tab:tab2Mechanical Properties of Silver-Palladium Alloys"><caption>'''<!--Table 2.18:-->Mechanical Properties of Silver-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">[%]min.19</p></th><th><p class="s12">Vickers Hardness</p><p class="s12">HV</p></th></tr><tr><td><p class="s12">AgPd30</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</p></td><td><p class="s12">72</p><p class="s12">165</p></td></tr><tr><td><p class="s12">AgPd50</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</p></td><td><p class="s12">85</p><p class="s12">195</p></td></tr><tr><td><p class="s12">AgPd30Cu5</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</p></td><td><p class="s12">90</p><p class="s12">190</p></td></tr></table></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>'

<figtable id="tab:tab2.20Application 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 border="1" cellspacingclass="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>

====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 (<xr id="fig:fig2.75Micro structure of AgNi9010"/> <!--(Fig. 2.75) --> and <xr id="fig:fig2.76Micro 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:tab2.21Physical Properties of Silver-Nickel (SINIDUR) Materials"/> )<!--(Tab 2.21) and <xr id="tab:tab2.22"/--> (Tab 2.22). The typical application of Ag/Ni contact materials is in devices for switching currents of up to 100A (<xr id="tab:tab2.24Application 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:tab2.23Contact and Switching Properties of Silver-Nickel (SINIDUR) Materials"/> )<!--(Table 2.23)-->.

Typically Ag/Ni (SINIDUR) materials are usually produced with contents of 10-40 wt% Ni. The most widely common used materials SINIDUR Ag/Ni 10 and SINIDUR Ag/Ni 20- and also SINIDUR Ag/Ni 15, mostly used in north america-, are easily formable and applied by cladding (<xr id="fig:fig2.71Strain hardening of AgNi9010 by cold working"/> ,<!--(Fig. 2.71) --> <xr id="fig:fig2.72Softening of AgNi9010 after annealing"/> ,<!--(Fig. 2.72) --> <xr id="fig:fig2.73Strain hardening of AgNi8020"/> , <!--(Fig. 2.73) --> <xr id="fig:fig2.74Softening 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 (SINIDUR) Ag/Ni materials with nickel contents of 30 and 40 wt% are used in switching devices , requiring a higher arc erosion resistance and where increasesin 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, auxiliaryswitches, and small contactors with nominal currents >20A (<xr id="tab:tab2.24Application Examples and Forms of Supply for Silver-Nickel (SINIDUR) Materials"/> )<!--(Table 2.24)-->.

<figtable id="tab:tab2.21Physical Properties of Silver-Nickel (SINIDUR) Materials"><caption>'''<!--Table 2.21: -->Physical Properties of Silver-Nickel (SINIDUR) Materials'''</caption><table border="1" cellspacing="0" styleclass="border-collapse:collapsetwocolortable"><tr><td><p class="s12"th>Material/</p><p class="s11">DODUCO <span style=" color: #151616;">Designation</span></p></tdth><td><p class="s12"th>Silver Content</p><p class="s12">[wt%]</p></tdth><td><p class="s12"th>Density</pth><p class="s11">[g/cm<span class="s13">3 </span><span style=" color: #151616;">]</span></p></td><td><p class="s12"th>Melting Point</pth><p class="s12">[°C]</pth></td><td><p class="s12">Electrical</p><p class="s12">Resistivity ElectricalResistivity<i>p</i></pth><p classth colspan="s11">[µ<span class="s14">S ·</span>cm]</p></td><td><p class="s122">Electrical Resistivity</p><p class="s11">(soft)</p></tdth></tr><tr><td><p class="s12">Material/</p><p class="s11">DODUCO <span style=" color: #151616;"th>Designation</spanth></p></td><td><p class="s12">Silver Content</p><p class="s12"th>[wt%]</pth></td><td><p class="s12">Density</p><p class="s11"th>[g/cm<span class="s13"sup>3 </span><span style=" color: #151616;"sup>]</span></p></td><td><p class="s12">Melting Point</pth><p class="s12"th>[°C]</p></td><td><p class="s12">Electrical</pth><p class="s12">Resistivity <i>p</i></p><p class="s11"th>[µ<span class="s14">S ·</span>cmµΩ·cm]</p></tdth><td><p class="s11"th>[% IACS]</pth></td><td><p class="s11"th>[MS/m]</p></tdth></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 - 10.2</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">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></table>

<caption>'''<!-- Table 2.22: -->Mechanical Properties of Silver-Nickel (SINIDUR) Materials'''</caption>

!Material/DODUCO-Designation

|Ag/Ni 90/10<br />SINIDUR 10

|Ag/Ni 85/15<br />SINIDUR 15

|Ag/Ni 80/20<br />SINIDUR 20

|Ag/Ni 70/30<br />SINIDUR 30

|Ag/Ni 60/40<br />SINIDUR 40

<figure id="fig:fig2.71Strain hardening of AgNi9010 by cold working">

<figure id="fig:fig2.72Softening of AgNi9010 after annealing">

<figure id="fig:fig2.73Strain hardening of AgNi8020">

<figure id="fig:fig2.74Softening of AgNi8020 after annealing">

<figure id="fig:fig2.75Micro structure of AgNi9010">

<figure id="fig:fig2.76Micro structure of AgNi 8020">

<figtable id="tab:tab2.23Contact and Switching Properties of Silver-Nickel (SINIDUR) Materials"><caption>'''<!-- Table 2.23: -->Contact and Switching Properties of Silver-Nickel (SINIDUR) Materials'''</caption>

!Material/DODUCO-Designation

|Ag/Ni <br />SINIDUR

<figtable id="tab:tab2.24Application Examples and Forms of Supply for Silver-Nickel (SINIDUR) Materials"><caption>'''<!--Table 2.24: -->Application Examples and Forms of Supply for Silver-Nickel (SINIDUR) Materials'''</caption>

|Relays ¤ Automotive Relays - <br />Automotive Relays - Resistive load - <br />Motor load

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 ''(Table 2.13)''. *'''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 oxygen rich atmosphere in 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 larger further away towards the center of the material <xr id="figtab:fig2.83Application Examples of Silver–Metal Oxide Materials"/> )<!--(Fig. Table 2.8331)-->.

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*'''Silver-drawing to the required diameter <xr id="fig:fig2.77"/> (Figs. 2.77) and <xr id="fig:fig2.78"/> (Fig. 2.78). The resulting material is used for example in the production of contact rivets. For Ag/CdO strip cadmium oxide 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 Ag backing suitable for easy attachment by brazing (sometimes called “Conventional Ag/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 easily brazable AgCd alloy backing <xr id="fig:fig2.85"/> (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 Silver-cadmium oxide materials with 10-15 wt% are typically converted produced by pressingboth, sintering internal oxidation 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:fig2.84"/> (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 <xr id="fig:fig2.86"/> (Fig. 2.86)powder metallurgical methods.

For larger contact tips, The manufacturing of strips and especially those wires by internal oxidation starts with a rounded shape, the single tip Press-Sinter-Repress process (PSR) offers economical advantagesmolten alloy of silver and cadmium. Thepowder mix is pressed During a heat treatment below it's melting point in an oxygen rich atmosphere of such a die close to homogeneous alloy, the oxygen diffuses from the surface into the final desired shape, bulk of the “green” tips are sintered, material and oxidizes the Cd to CdO in most cases a more or less fine particle precipitation inside the repress process forms Ag matrix. The CdO particles are rather fine in the final exact shape while at surface area and getting larger towards the same time increasing center of the contact density and hardnessmaterial (<xr id="fig:Micro structure of AgCdO9010"/>)<!--(Fig. 2.83)-->.

Using different 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 powders , followed by complete oxidation, results in a strip material with a small depletion area in the center of it's thickness and minor additives an Ag backing suitable for easy attachment by brazing (sometimes called "Conventional Ag/CdO"). Using a technology that allows the basic partial oxidation of a dual-strip AgCd alloy material in a higher pressure pure oxygen atmosphere, yields a composite Ag and /CdO strip material that has - besides a relatively fine CdO starting precipitation - also an easily brazable AgCd alloy backing. These materials can help influence certain are mainly used as the basis for contact properties for specialized applicationsprofiles and contact tips.

During powder metallurgical production, the powder mixed made by different processes are typically converted by pressing, sintering and extrusion to wires and 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:fig2.77Micro structure of AgCdO9010P"/> )<!--(Fig. 2.77: Strain hardening of internally oxidized Ag/CdO 90/10 84)-->. To obtain a backing suitable for brazing, a fine silver layer is applied by cold workingeither com-pound extrusion or hot cladding prior to or right after the extrusion.

<xr id=For larger contact tips, and especially those with a rounded shape, the single tip Press-Sinter-Repress process (PSR) offers economical advantages. The powder mix is pressed into a die close to the final desired shape, the "fig:fig2.78green"/> Fig. 2tips are sintered, and in most cases, the repress process forms the exact final shape while at the same time, increasing the contact density and hardness.78: Softening of internally oxidized Ag/CdO 90/10 after annealing for 1 hr after 40% cold working

<xr id="fig:fig2.79"/> Fig. 2.79: Strain hardening of Ag/CdO 90/10 P by cold working <xr id="fig:fig2.80"/> Fig. 2.80: Softening of Ag/CdO 90/10 P after annealing Using different silver powders and minor additives for 1 hr after 40% cold working <xr id="fig:fig2.81"/> Fig. 2.81: Strain hardening of Ag/CdO 88/12 WP <xr id="fig:fig2.82"/> Fig. 2.82: Softening of the basic Ag/and CdO 88/12WP after annealing , starting materials can help influence certain contact properties for 1 hr after different degrees of cold working <xr id="fig:fig2.83"/> Fig. 2.83: Micro structure of Ag/CdO 90/10 i.o. a) close to surface b) in center area <xr id="fig:fig2.84"/> Fig. 2.84: Micro structure of Ag/CdO 90/10 P: a) perpendicular to extrusion direction b) parallel to extrusion direction <xr id="fig:fig2.85"/> Fig. 2.85: Micro structure of Ag/CdO 90/10 ZH: 1) Ag/CdO layer 2) AgCd backing layer <xr id="fig:fig2.86"/> Fig. 2specialized applications.86: Micro structure of AgCdO 88/12 WP: a) perpendicular to extrusion direction b) parallel to extrusion direction

<figure id="fig:fig2.77Strain hardening of internally oxidized AgCdO9010">

<figure id="fig:fig2.78Softening of internally oxidized AgCdO9010">[[File:Softening of internally oxidized AgCdO9010.jpg|left|thumb|<caption>Softening of internally oxidized (i.o.) Ag/CdO 90/10 after annealing for 1 hr after 40% cold working</caption>]]

<figure id="fig:fig2.79Strain hardening of AgCdO9010P">[[File:Strain hardening of AgCdO9010P.jpg|left|thumb|<caption>Strain hardening of powder metallurgical (p.m.) Ag/CdO 90/10 P by cold working</caption>]]

<figure id="fig:fig2.80Softening of AgCdO9010P after annealing">[[File:Softening of AgCdO9010P after annealing.jpg|left|thumb|<caption>Softening of powder metallurgical Ag/CdO 90/10 P after annealing for 1 hr after 40% cold working</caption>]]

<figure id="fig:fig2.81Strain hardening of AgCdO8812">[[File:Strain hardening of AgCdO8812.jpg|left|thumb|<caption>Strain hardening of powder metallurgical Ag/CdO 88/12 WP</caption>]]

<figure id="fig:fig2.82Softening of AgCdO8812WP after annealing">[[File:Softening of AgCdO8812WP after annealing.jpg|left|thumb|<caption>Softening of powder metallurgical Ag/CdO 88/12WP 12 after annealing for 1 hr after different degrees of cold working</caption>]]

<figure id="fig:fig2.83Micro structure of AgCdO9010">

<figure id="fig:fig2.84Micro structure of AgCdO9010P">[[File:Micro structure of AgCdO9010P.jpg|left|thumb|<caption>Micro structure of Ag/CdO 90/10 Pp.m.: a) perpendicular to extrusion direction b) parallel to extrusion direction</caption>]]</figure> <figure id="fig:fig2.85">[[File:Micro structure of AgCdO9010ZH.jpg|left|thumb|<caption>Micro structure of Ag/CdO 90/10 ZH: 1) Ag/CdO layer 2) AgCd backing layer</caption>]]

*'''Table 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.25This 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: Physical Contact and Mechanical Switching Properties as well as Manufacturing Processes and Forms of Supply Silver–Metal Oxide Materials"/>)<!--(Table 2.30)-->. Ag/SnO₂ materials have been optimized for a broad range of Extruded Silver Cadmium Oxide 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"/><!--(DODURIT CdOTab. 2.28)--> and <xr id="tab:tab2.29"/>) Contact Materials'''nicht gemacht<!--(Table 2.29)-->.

 *'''Silver–tin oxide(SISTADOX)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:tab2.30"/> (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:tab2.29"/> (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) <xr id="fig:fig2.114"/> (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 WTOS F) <xr id="fig:fig2.116Micro 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:tab2.31Application 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 (SISTADOX) Contact Materials''' nicht gemacht!</caption>

====DEV:LIST====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 <xrlabel id{| class="fig:figlisttwocolortable" groupstyle="figtext-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:'''a) |Powder blending from single component powders''' Metallurgy|1,2|-|Ag/SnO₂ 88/12 PMT1|87 - 89|Bi<brsub>2</sub>O₃ 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.and CuO|9,9|46 ± 5||260|20:'''b) |Powder blending on the basis of doped powders''' Metallurgy|1,2|-|Ag/SnO₂ 90/10 PE|89 - 91|Bi₂O<sub>3<br/sub> For incorporation of additive oxides in the and CuO|9,8|48 ± 2|55 - 100|230 - 330|28|Powder Metallurgy|1|-|Ag/SnO₂ powder the reactive spray process (RSV) has shown advantages. This process starts with a waterbased solution of the tin 88/12 PE|87 - 89|Bi₂O₃ and other metal compounds. This solution is nebulized under high pressure 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 temperature in a reactor chamber. Through the rapid evaporation of the water each small droplet is converted into a salt crystal CuO|9,8||95 ± 10|||Powder Metallurgy|2|-|Ag/SnO₂ 94/6 LC1|93 - 95|Bi₂O₃ 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.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 |In₂O₃|9,6|45 ± 5|95 ± 15|330|20|Internal Oxidation|1,2|-|}</figtable>

:'''c) Powder blending based on coated oxide powders''' <br> In this process tin oxide powder is blended with lower meting additive oxides such as for example Ag_{1 = Wires, Rods, Contact rivets, 2} MoO₄ and then heat treated. The SnO₂ particles are coated in this step with a thin layer of the additive oxide.= 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::'''ea) Powder blending based on chemically precipitated compound from single component 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 this common process all components, including additives that are precipitated around part of the additive metal oxide particles who act powder mix, are blended as crystallization sitessingle powders. Further chemical treatment then reduces the silver oxide with The blending is usually performed in the resulting precipitated powder being a mix dry stage in blenders of Ag and SnO₂different design.

Further processing :'''b) Powder blending on the basis of these differently produced doped powders follows ''' <br> For incorporation of additive oxides in the conventional processes SnO₂ powder, the reactive spray process has shown advantages. This process starts with a waterbased solution of pressing, sintering the tin and hot extrusion to wires other metal compounds. This solution is nebulized under high pressure and stripstemperature in a reactor chamber. From these contact parts such as contact rivets Through the rapid evaporation of the water, each small droplet is converted into a salt crystal and tips are manufactured. To obtain from there gets transformed by oxidation into a brazable backing tin oxide particle in which the same processes additive metals are distributed evenly as used for Ag/CdO are appliedoxides. As for Ag/CdO, larger contact tips can also be manufactured more economically using the press-sinter-repress (PSR) process The so created doped AgSnO<sub>2<xr id="tab:tab2.27"/sub> (Table 2.27)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 melting additive oxides such as for example Ag₂ MoO<sub>4<xr id="fig:fig2.87"/sub> Figand then heat treated. 2.87: Strain hardening of Ag/The SnO₂ 92/8 PE by cold workingparticles are coated in this step with a thin layer of the additive oxide.

<xr id="fig:fig2.88"/> Fig. 2.88: Softening of Ag/SnO₂ 92/8 PE after annealing for 1 hr after 40% cold working <xr id="fig:fig2.89"/> Fig. 2.89: Strain hardening of Ag/SnO₂ 88/12 PE by cold working <xr id="fig:fig2.90"/> Fig. 2.90: Softening of Ag/SnO₂ 88/12 PE after annealing for 1 hr after 40% cold working <xr id="fig:fig2.91"/> Fig. 2.91: Strain hardening of oxidized Ag/SnO₂ 88/12 PW4 by cold working <xr id="fig:fig2.92"/> Fig. 2.92: Softening of Ag/SnO₂ 88/12 PW4 after annealing for 1 hr after 30% cold working <xr id="fig:fig2.93"/> Fig. 2.93: Strain hardening of Ag/SnO₂ 98/2 PX by cold working <xr id="fig:fig2.94"/> Fig. 2.94: Softening of Ag/SnO₂ 98/2 PX after annealing for 1 hr after 80% cold working <xr id="fig:fig2.95"/> Fig 2.95: Strain hardening of Ag/SnO₂ 92/8 PX by cold working <xr id="fig:fig2.96"/> Fig. 2.96: Softening of Ag/SnO₂ 92/8 PX after annealing for 1 hr after 40% cold working <xr id="fig:fig2.97"/> Fig. 2.97: Strain hardening of '''d) Powder blending based on internally oxidized Ag/SnOalloy powders''' <subbr>2</sub> 88/12 TOS F by cold working <xr id="fig:fig2.98"/> Fig. 2.98: Softening A combination of powder metallurgy and internal oxidation this process starts with atomized Ag/SnO₂ 88/12 TOS F after annealing for 1 hr after 30% cold working <xr id="fig:fig2.99"/> Fig. 2.99: Strain hardening of internally alloy powder which is subsequently oxidized Ag/SnO₂ 88/12P by cold working <xr id="fig:fig2.100"/> Fig. 2.100: Softening of Ag/SnO₂ 88/12P after annealing for 1 hr after 40% cold working <xr id="fig:fig2.101"/> Fig. 2.101: Strain hardening of Ag/SnO₂ 88/12 WPC by cold working <xr id="fig:fig2in pure oxygen.102"/> Fig. 2.102: Softening of Ag/SnO₂ 88/12 WPC after annealing for 1 hr after different degrees of cold working <xr id="fig:fig2.103"/> Fig. 2.103: Strain hardening of Ag/SnO₂ 86/14 WPC by cold working <xr id="fig:fig2.104"/> Fig. 2.104: Softening of Ag/SnO₂ 86/14 WPC after annealing for 1 hr after different degrees of cold working <xr id="fig:fig2.105"/> Fig. 2.105: Strain hardening of Ag/SnO₂ 88/12 WPD by cold working <xr id="fig:fig2.106"/> Fig. 2.106: Softening of Ag/SnO₂ 88/12 WPD after annealing for 1 hr after different degrees of cold working <xr id="fig:fig2.108"/> Fig. 2.108: Softening of Ag/SnO₂ 88/12 WPX after annealing for 1 hr after different degrees of cold working <xr id="fig:fig2.107"/> Fig. 2.107: Strain hardening of Ag/SnO₂ 88/12 WPX by cold working <xr id="fig:fig2.109"/> Fig. 2.109: Micro structure of Ag/SnO₂ 92/8 PE: a) perpendicular to extrusion directionb) parallel During this process the Sn and other metal components are transformed to extrusion direction <xr id="fig:fig2.110"/> Fig. 2.110: Micro structure metal oxide and precipitated inside the silver matrix of Ag/SnO₂ 88/12 PE: a) perpendicular to extrusion directionb) parallel to extrusion direction <xr id="fig:fig2.111"/> Fig. 2.111: Micro structure of Ag/SnO₂ 88/12 PW: a) perpendicular to extrusion directionb) parallel to extrusion direction <xr id="fig:fig2.112"/> Fig. 2.112: Micro structure of Ag/SnO₂ 98/2 PX: a) perpendicular to extrusion directionb) parallel to extrusion direction <xr id="fig:fig2.113"/> Fig. 2.113: Micro structure of Ag/SnO₂ 92/8 PX: a) perpendicular to extrusion directionb) parallel to extrusion direction <xr id="fig:fig2.114"/> Fig. 2.114: Micro structure of Ag/SnO₂ 88/12 TOS F: a) perpendicular to extrusion directionb) parallel to extrusion direction <xr id="fig:fig2each powder particle.115"/> Fig. 2.115: Micro structure of Ag/SnO₂ 86/14 WPC: a) perpendicular to extrusion directionb) parallel to extrusion direction, 1) AgSnO₂ contact layer, 2) Ag backing layer

:'''e) Powder blending based on chemically precipitated compound powders''' <xr id="fig:fig2.116"/br> Fig. 2.116: Micro structure A silver salt solution is added to a suspension of Ag/for example SnO₂ 92/8 WTOS F: together with a precipitation agent. In a) perpendicular to extrusion directionb) parallel to extrusion directionchemical reaction,1) AgSnO₂ contact layersilver and silver oxide respectively are precipitated around the additive metal oxide particles, 2) Ag backing layer <xr id="fig:fig2who act as crystallization sites.117"/> Fig. 2.117: Micro structure of Ag/SnO₂ 88/12 WPD: parallel to extrusion direction1) AgSnO₂ contact layerFurther chemical treatment then reduces the silver oxide with the resulting precipitated powder, 2) Ag backing layer <xr id="fig:fig2.118"/> Fig. 2.118: Micro structure being a mix of Ag/and SnO₂ 88/12 WPX:parallel to extrusion direction1) AgSnO₂ contact layer, 2) Ag backing layer <xr id="fig:fig2.119"/> Fig. 2.119: Micro structure of Ag/SnO₂ 86/14 WPX: a) perpendicular to extrusion directionb) parallel to extrusion direction, 1) AgSnO₂ contact layer, 2) Ag backing layer

<figure id="fig:fig2.87Strain hardening of AgSNO2 92 8 PE">

<figure id="fig:fig2.88Softening of AgSnO2 92 8 PE">

<figure id="fig:fig2.89Strain hardening of Ag SnO2 88 12 PE">

<figure id="fig:fig2.90Softening of Ag SnO2 88 12 PE after annealing">

<figure id="fig:fig2.91Strain hardening of oxidized AgSnO2 88 12 PW4">

<figure id="fig:fig2.92Softening of Ag SnO2 88 12 PW4 after annealing">

<figure id="fig:fig2.93Strain hardening of internally oxidized Ag SnO2 88 12 TOS F"> [[File:Strain hardening of internally oxidized Ag SnO2 98 2 PX88 12 TOS F.jpg|left|thumb|<caption>Strain hardening of internally oxidized Ag/SnO₂ 9888/2 PX 12 TOS F by cold working</caption>]]

<figure id="fig:fig2.94Softening of Ag SnO2 88 12 TOS F after annealing"> [[File:Softening of Ag SnO2 98 2 PX 88 12 TOS F after annealing.jpg|left|thumb|<caption>Softening of Ag/SnO₂ 9888/2 PX 12 TOS F after annealing for 1 hr after 8030% cold working</caption>]]

<figure id="fig:fig2.95Strain hardening of internally oxidized Ag SnO2 88 12P">[[File:Strain hardening of internally oxidized Ag SnO2 92 8 PX88 12P.jpg|left|thumb|<caption>Strain hardening of internally oxidized Ag/SnO₂ 9288/8 PX 12P by cold working</caption>]]

<figure id="fig:fig2.96Softening of Ag SnO2 88 12P after annealing"> [[File:Softening of Ag SnO2 92 8 PX 88 12P after annealing.jpg|left|thumb|<caption>Softening of Ag/SnO₂ 9288/8 PX 12 SP after annealing for 1 hr after 40% cold working</caption>]]

<figure id="fig:fig2.97Strain hardening of Ag SnO2 88 12 WPD"> [[File:Strain hardening of internally oxidized Ag SnO2 88 12 TOS FWPD.jpg|left|thumb|<caption>Strain hardening of internally oxidized Ag/SnO₂ 88/12 TOS F WPD by cold working</caption>]]

<figure id="fig:fig2.98Softening of Ag SnO2 88 12 WPD after annealing"> [[File:Softening of Ag SnO2 88 12 TOS F WPD after annealing.jpg|left|thumb|<caption>Softening of Ag/SnO₂ 88/12 TOS F WPD after annealing for 1 hr after 30% different degrees of cold working</caption>]]

<figure id="fig:fig2.99Micro structure of Ag SnO2 92 8 PE"> [[File:Strain hardening Micro structure of internally oxidized Ag SnO2 88 12P92 8 PE.jpg|left|thumb|<caption>Strain hardening Micro structure of internally oxidized Ag/SnO₂ 8892/12P by cold working8 PE: a) perpendicular to extrusion direction b) parallel to extrusion direction</caption>]]

<figure id="fig:fig2.100Micro structure of Ag SnO2 88 12 PE"> [[File:Softening Micro structure of Ag SnO2 88 12P after annealing12 PE.jpg|left|thumb|<caption>Softening Micro structure of Ag/SnO₂88/12P after annealing for 1 hr after 40% cold working12 PE: a) perpendicular to extrusion direction b) parallel to extrusion direction</caption>]]

<figure id="fig:fig2.101Micro structure of Ag SnO2 88 12 PW"> [[File:Strain hardening Micro structure of Ag SnO2 88 12 WPCPW.jpg|left|thumb|<caption>Strain hardening Micro structure of Ag/SnO₂ 88/12 WPC by cold workingSPW: a) perpendicular to extrusion direction b) parallel to extrusion direction</caption>]]

<figure id="fig:fig2.102Micro structure of Ag SnO2 88 12 TOS F"> [[File:Softening Micro structure of Ag SnO2 88 12 WPC after annealingTOS F.jpg|left|thumb|<caption>Softening Micro structure of Ag/SnO₂ 88/12 WPC after annealing for 1 hr after different degrees of cold workingTOS F: a) perpendicular to extrusion direction b) parallel to extrusion direction</caption>]]

<figure id="fig:fig2.103Micro structure of Ag SnO2 92 8 WTOS F"> [[File:Strain hardening Micro structure of Ag SnO2 86 14 WPC92 8 WTOS F.jpg|left|thumb|<caption>Strain hardening Micro structure of Ag/SnO₂ 8692/14 WPC by cold working8 WTOS F: a) perpendicular to extrusion direction b) parallel to extrusion direction,1) AgSnO2 contact layer, 2) Ag backing layer</caption>]]

<figure id="fig:fig2.104Micro structure of Ag SnO2 88 12 WPD"> [[File:Softening Micro structure of Ag SnO2 86 14 WPC88 12 WPD.jpg|left|thumb|<caption>Softening Micro structure of Ag/SnO₂ 8688/14 WPC after annealing for 12 WPD: parallel to extrusion direction 1 hr after different degrees of cold working) AgSnO2 contact layer, 2) Ag backing layer</caption>]]

<figure iddiv class="fig:fig2.105clear"> [[File:Strain hardening of Ag SnO2 88 12 WPD.jpg|left|thumb|<caption>Strain hardening of Ag/SnO₂ 88/12 WPD by cold working</caption>]]</figurediv>

<figure figtable id="figtab:fig2Physical Properties of Powder Metallurgical Silver-Metal Oxide Materials with Fine Silver Backing Produced by the Press-Sinter-Repress Process"><caption>'''<!--Table 2.10827:-->Physical Properties of Powder 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> <tr><th><p class="s11">[%IACS]</p></th><th><p>[File:Softening of Ag SnO2 88 12 WPXMS/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.jpg|left|thumb|22</p><caption/td><td><p class="s12">78</p></td><td><p class="s12">45</p></td><td><p class="s11">55</p></td>Softening of Ag</SnOtr><tr><td><p class="s11">AgSnO₂ 88/12 WPX after annealing for 1 hr after different degrees of cold working</captionp></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 tips</figurefigtable>

*'''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)]]<figure id="fig:fig2!--(Table 2.28)-->.107"Adding WO₃ [[File:Strain hardening of or Ag SnO2 88 12 WPX.jpg|left|thumb|<captionsub>2</sub>WO₄Strain hardening of 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 by cold workingZnO materials present an economic alternative to Cd free Ag-tin oxide contact materials (<xr id="tab:Contact and Switching Properties of Silver–Metal Oxide Materials"/caption>]]<!--(Tab. 2.30)--> and <xr id="tab:Application Examples of Silver–Metal Oxide Materials"/figure>)<!--(Tab. 2.31)-->.

<figure figtable id="figtab:fig2tab2.11028"> [[File:Micro structure of Ag SnO2 88 12 PE.jpg|left|thumb|<caption>Micro structure of Ag/SnO'''<sub>!--Table 2</sub.28:--> 88/12 PE: a) perpendicular to extrusion direction b) parallel to extrusion directionPhysical and Mechanical Properties as well as Manufacturing Processes and Forms of Supply of Extruded Silver-Zinc Oxide Contact'''</caption>]]</figure>

{| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material !Silver Content<br />[wt%]!Additives!Density<br />[g/cm³]!Electrical<br />Resistivity<figure idbr />[μΩ·cm]!colspan="2" style="figtext-align:fig2.111center"|Electrical<br />Conductivity<br />[% IACS] [MS/m]!Vickers<br />Hardness<br /> Hv1!Tensile<br />Strength<br />[MPa]!Elongation<br />(soft annealed)<br />A[File:Micro structure %]min.!Manufacturing<br />Process!Form of <br />Supply|-|Ag SnO2 88 12 PW/ZnO 92/8P<br />|91 - 93||9.8|2.jpg22|78|45|60 - 95|left220 - 350|thumb25|Powder Metallurgy<captionbr />Micro structure of a) indiv. powders|1|-|Ag/SnOZnO 92/8PW25<br />|91 - 93|Ag₂ 88WO<sub>4</12 PW: sub>|9.6|2.08|83|48|65 - 105|230 - 340|25|Powder Metallurgy<br />c) coated|1|-|Ag/ZnO 90/10PW25<br />|89 - 91|Ag₂WO₄|9.6|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 Ag backing a) perpendicular to extrusion direction bindivid.|2|-|Ag/ZnO 92/8WPW25<br />|91 - 93|Ag₂WO₄|9.6|2.08|83|48|65 - 105|||Powder Metallurgy<br />c) parallel to extrusion directioncoated|2|-|Ag/ZnO 90/10WPW25<br />|89 - 91|Ag₂WO<sub>4</captionsub>]]|9.6|2.7|79|46|65 - 110|||Powder Metallurgy<br />c) coated|2|}</figurefigtable>

<figure id1 ="fig:fig2.112"> [[File:Micro structure of Ag SnO2 98 Wires, Rods, Contact rivets, 2 PX.jpg|left|thumb|<caption>Micro structure of Ag/SnO₂ 98/2 PX: a) perpendicular to extrusion direction b) parallel to extrusion direction</caption>]]</figure>= Strips, Profiles, Contact tips

<div class="multiple-images"><figure id="fig:fig2.114Strain hardening of Ag ZnO 92 8 PW25"> [[File:Micro structure Strain hardening of Ag SnO2 88 12 TOS FZnO 92 8 PW25.jpg|left|thumb|<caption>Micro structure Strain hardening of Ag/SnO<sub>2<ZnO 92/sub> 88/12 TOS F: a) perpendicular to extrusion direction b) parallel to extrusion direction8 PW25 by cold working</caption>]]

<figure id="fig:fig2.115Softening of Ag ZnO 92 8 PW25"> [[File:Micro structure Softening of Ag SnO2 86 14 WPCZnO 92 8 PW25.jpg|left|thumb|<caption>Micro structure Softening of Ag/SnO₂ 86ZnO 92/14 WPC: a) perpendicular to extrusion direction b) parallel to extrusion direction, 8 PW25 after annealing for 1) AgSnO2 contact layer, 2) Ag backing layerhr after 30% cold working</caption>]]

<figure id="fig:fig2.116Strain hardening of Ag ZnO 92 8 WPW25"> [[File:Micro structure Strain hardening of Ag SnO2 ZnO 92 8 WTOS FWPW25.jpg|left|thumb|<caption>Micro structure Strain hardening of Ag/SnO₂ ZnO 92/8 WTOS F: a) perpendicular to extrusion direction b) parallel to extrusion direction,1) AgSnO2 contact layer, 2) Ag backing layerWPW25 by cold working</caption>]]

<figure id="fig:fig2.117Softening of Ag ZnO 92 8 WPW25"> [[File:Micro structure Softening of Ag SnO2 88 12 WPDZnO 92 8 WPW25.jpg|left|thumb|<caption>Micro structure Softening of Ag/SnO<sub>2<ZnO 92/sub> 88/12 WPD: parallel to extrusion direction 1) AgSnO2 contact layer, 2) Ag backing layer8 WPW25 after annealing for 1hr after different degrees of cold working</caption>]]

<figure id="fig:fig2.118Micro structure of Ag ZnO 92 8 PW25"> [[File:Micro structure of Ag SnO2 88 12 WPXZnO 92 8 Pw25.jpg|left|thumb|<caption>Micro structure of Ag/SnO₂ 88ZnO 92/12 WPX8 PW25:a) perpendicular to extrusion direction b) parallel to extrusion direction 1) AgSnO2 contact layer, 2) Ag backing layer</caption>]]

<figure id="fig:fig2.119Micro structure of Ag ZnO 92 8 WPW25"> [[File:Micro structure of Ag SnO2 86 14 WPXZnO 92 8 WPW25.jpg|leftright|thumb|<caption>Micro structure of Ag/SnO₂ 86ZnO 92/14 WPX8 WPW25: a) perpendicular to extrusion direction b) parallel to extrusion direction, 1) AgSnO2 Ag/ZnO contact layer, 2) Ag backing layer</caption>]]

<caption>'''<!--Table 2.29: -->Optimizing of Silver–Tin Oxide Materials Regarding their Switching Properties and Forming Behavior'''</caption><table borderclass="1" cellspacing="0" style="border-collapse:collapsetwocolortable"><tr><tdth><p class="s12">Material/</p><p class="s12">Material Group</p></tdth><tdth><p class="s12">Special Properties<th colspan="2"></p></tdth></tr><tr><td><p class="s12">Ag/SnO<span class="s48"sub>2 </spansub>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/SnO<span class="s48">2 </span>98/2 PX/PC</p></td><td><p class="s12">Especially good heat resistance</p></td><td><p class="s12">Easily riveted, can be directly welded</p></td></tr><tr><td><p class="s12">Ag/SnO<span class="s48"sub>2 </spansub>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/SnO<span class="s48">2 </span>WPC</p></td><td><p class="s12">For AC-3 and AC-4 applications in motor</p><p class="s12">switches (contactors)</p></td><td/></tr><tr><td><p class="s12">Ag/SnO<span class="s48"sub>2 </spansub>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/SnO<span class="s48"sub>2 </spansub>WPX</p></td><td><p class="s12">For standard motor loads (AC-3) and</p><p class="s12">Resistive loads (AC-1), DC loads (DC-5)</p></td><td/></tr><tr><td><p class="s12">Ag/SnO<span class="s48">2 </span>WTOSFW 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 id="tab:tab2.30Contact and Switching Properties of Silver–Metal Oxide Materials"><caption>'''<!--Table 2.30: -->Contact and Switching Properties of Silver–Metal Oxide Materials'''</caption>

!Material/DODUCO-Designation

|Ag/CdO<br />DODURIT CdO|High resistance against welding during current on switching for currents up to<br />5kA especially for powder metallurgical materials,<br />Weld resistance increases with higher oxide contents,<br />Low and stable contact resistance over the life of the device and good<br />temperature rise properties,<br />High arc erosion resistance and contact life at switching currents<br />of 100A – 5kA,<br />Very good arc moving properties for materials produced by internal oxidation,<br />Good arc extinguishing properties,<br />Formability better than the one of Ag/SnO2 and Ag/ZnO materials,<br />Use of Ag/CdO in automotive components is prohibited because of Cd toxicity,<br />Prohibition of use in consumer products and appliances in EU.|-|Ag/SnO₂<br />SISTADOX

Very high resistance against welding during current -on -switching,<br />Weld resistance increases with higher oxide contents,<br />

|Ag/ZnO<br />DODURIT ZnO

High resistance against welding during current -on -switching<br />(capacitor contactors),<br />

 <figtable id="tab:tab2.31Application Examples of Silver–Metal Oxide Materials"><caption>'''<!--Table 2.31: -->Application Examples of Silver–Metal Oxide Materials'''</caption><table border="1" cellspacing="0" styleclass="border-collapse:collapsetwocolortable"><tr><tdth><p class="s12">Material</p></tdth><tdth><p class="s12">Application Examples</p></tdth></tr><tr><td><p class="s12">Ag/CdOSnO</p></td><td><p class="s12">Micro switches, Network relays, Wiring devices, Appliance switches, Main switches, contactors, Small (main) power switches</p></tdsub>2</tr><tr><td><p class="s12"sub>Ag/SnO<span class="s48">2</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), (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 Ag/Ni or Ag/C), Fault current circuit breakers paired againct Ag/C, (Main) Power switches</p></td></tr></table>

====Silver–Graphite (GRAPHOR)-Materials====Ag/C (GRAPHOR) contact materials are usually produced by powder metallurgy with graphite contents of 2 – 5 6 wt% ''(<xr id="tab:tab2.32"/>)<!--(Table 2.32)''-->. The earlier typicalmanufacturing process of single pressed tips by pressing - sintering - repressing (PSR) has been replaced in Europe for quite some time by extrusion. In North America and some other regions however the PSR process is still used to some extend mainly for cost reasons.

The extrusion of sintered billets is now the dominant manufacturing method for semi-finished AgC materials ''<!--[[#figures3|(Figs. 64 – 67)]]<!--(Figs. 2.126 – 2.129)''-->. The hot extrusion process results in a high density material with graphite particles stretched and oriented in the extrusion direction ''[[#figures4|(Figs. 68 – 71)]]<!--(Figs. 2.130 – 2.133)''-->. Depending on the extrusion method in either rod or strip form , the graphite particles can be oriented in the finished contact tips perpendicular (GRAPHOR) or parallel (GRAPHOR D) to the switching contact surface ''(Figs<xr id="fig:Micro structure of Ag C 95 5"/><!--(Fig. 2.131 )--> and <xr id="fig:Micro structure of Ag C 96 4 D"/>)<!--(Fig. 2.132)''-->.

Since the graphite particles in the Ag matrix of Ag/C materials prevent contact tips from directly being welded or brazed, a graphite free bottom layer is required. This is achieved by either burning out (de-graphitizing) the graphite selectively on one side of the tips or by compound extrusion of a Ag/C billet covered with a fine silver shell.

Ag/C contact materials exhibit on the one hand an extremely high resistance to contact welding but on the other have a low arc erosion resistance. This is caused by the reaction of graphite with the oxygen in the surrounding atmosphere at the high temperatures created by the arcing. The weld resistanceis especially high for materials with the graphite particle orientation parallel to the arcing contact surface. Since the contact surface after arcing consists of pure silver , the contact resistance stays consistently consistantly low during the electrical life of the contact parts.

A disadvantage of the Ag/C materials is their rather high erosion rate. In 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 (GRAPHOR <xr id="fig:Micro structure of Ag C DF"/>), ''<!--(Fig. 2.133)''-->. The weld resistance is determined by the total content of graphite particles.

Ag/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 2.33)''-->. For attachment of Ag/C tips welding and brazing techniques are applied.

welding Welding the actual process depends on the material's graphite orientation. For Ag/C tips with vertical graphite orientation the contacts are assembled with single tips. 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 profile tapes GRAPHOR D and DF can be pre-coated with a thin layer of high temperature brazing alloys such as CuAgP.

The 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 2.34)''-->. For higher currents the low arc erosion resistance of Ag/C is compensated by asymmetrical pairing with more erosion resistant materials such as Ag/Ni , Ag/W and Ag/WWC.

Fig. 2.126<div class="multiple-images"><figure id="fig: Strain hardening of Ag/C 96/4 D by cold working">[[File:Strain hardening of Ag C 96 4 D.jpg|rightleft|thumb|<caption>Strain hardening of Ag/C 96/4 D by cold working</caption>]]</figure>

Fig. 2.127<figure id="fig: Softening of Ag/C 96/4 D after annealing"> [[File:Softening of Ag C 96 4 D.jpg|rightleft|thumb|<caption>Softening of Ag/C 96/4 D after annealing</caption>]]</figure>

Fig. 2.128<figure id="fig: Strain hardening of Ag/C DF by cold working"> [[File:Strain hardening of Ag C DF.jpg|rightleft|thumb|<caption>Strain hardening of Ag/C DF by cold working</caption>]]</figure>

Fig. 2.129<figure id="fig: Softening of Ag/C DF after annealing"> [[File:Softening of Ag C DF after annealing.jpg|rightleft|thumb|<caption>Softening of Ag/C DF after annealing</caption>]]</figure>

Fig. 2.130<figure id="fig: Micro structure of Ag/C 97/3: a) perpendicular to extrusion directionb) parallel to extrusion direction, 1) Ag/C contact layer, 2) Ag backing layer"> [[File:Micro structure of Ag C 97 3.jpg|rightleft|thumb|<caption>Micro structure of Ag/C 97/3: a) perpendicular to extrusion direction b) parallel to extrusion direction, 1) Ag/C contact layer, 2) Ag backing layer</caption>]]</figure>

Fig. 2.131<figure id="fig: Micro structure of Ag/C 95/5: a) perpendicular to extrusion directionb) parallel to extrusion direction, 1) Ag/C contact layer, 2) Ag backing layer"> [[File:Micro structure of Ag C 95 5.jpg|rightleft|thumb|<caption>Micro structure of Ag/C 95/5: a) perpendicular to extrusion direction b) parallel to extrusion direction, 1) Ag/C contact layer, 2) Ag backing layer</caption>]]</figure>

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

Fig. 2.133<figure id="fig: Micro structure of Ag/C DF: a) perpendicular to extrusion directionb) parallel to extrusion direction, 1) Ag/C contact layer, 2) Ag/Ni 90/10 backing layer"> [[File:Micro structure of Ag C DF.jpg|rightleft|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 (GRAPHOR) Contact Materials'''</caption>

'''Table 2.33: Contact and Switching properties of Silver–Graphite (GRAPHOR) Contact Materials'''<table border="1" cellspacing{| class="0twocolortable" style="bordertext-collapsealign:collapseleft; font-size: 12px">|-!Material !Silver Content<trbr />[wt%]!Density<tdbr />[g/cm<p class="s12"sup>Material/3</psup>]!Melting Point<p class="s12">DODUCO-Designation<br /p>[°C]!Electrical Resistivity<br /td><td><p class[μΩ·cm]!colspan="2" style="s11text-align:center">Properties|Electrical<br /p>Conductivity<br /td>[% IACS] [MS/m]!Vickers-Hardnes<br /tr>HV10<tr><td><p class="s12"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/p><p class="s12">GRAPHOR<C 97/p><3|96.5 - 97.5|9.1|960|1.92 - 2.0|86 - 90|45 - 48|41 - 43|-|Ag/td><td><p class="s12">Highest resistance against welding during make operations at high currents,<C 96/p><p class="s12">High resistance against welding of closed contacts during short circuit,<4|95.5 - 96.5|8.7|960|2.04 - 2.13|81 - 84|42 - 46|40 - 42|-|Ag/p><p class="s12">Increase of weld resistance with higher graphite contents, Low contact resistance,<C 95/p><p class="s12">Low arc erosion resistance, especially during break operations, Higher arc erosion with increasing graphite contents, at the same time carbon build5|94.5 - 95.5|8.5|960|2.12 - 2.22|78 - 81|40 - 44|40 - 60|-up on switching chamber walls increases, GRAPHOR with vertical orientation has better arc erosion resistance, parallel orientation has better weld resistance,|AgC DF<br /p>GRAPHOR DF[[#text-reference1|<p class="s12"sup>Limited arc moving properties, therefore paired with other materials,1</psup>]]|95.7 - 96.7|8.7 - 8.9|960|2.27 - 2.50|69 - 76|40 - 44|-|}<p classdiv id="s12text-reference1">Limited formability,</psub>1<p class="s12"/sub>Can be welded and brazed with decarbonized backingGraphite content 3.8 wt%, GRAPHOR DF is optimized for arc erosion resistance Graphite particles and weld resistancefibers parallel to switching surface</p></td></trdiv></tablefigtable>

   <figtable id="tab:tab2.33"><caption>'''<!--Table 2.3433: Application Examples -->Contact and Forms Switching properties of Supply of Silver– Graphite (GRAPHOR) Silver–Graphite Contact Materials'''</caption><table border="1" cellspacingclass="0" style="border-collapse:collapsetwocolortable"><tr><tdth><p class="s12">Material</p></p></th><th><p class="s12s11">DODUCO DesignationProperties</p></tdth></tr><tr><td><p class="s12">Application ExamplesAg/C</p></p></td><td><p class="s12">Form of SupplyHighest resistance against welding during make operations at high currents,</p></tdp class="s12">High resistance against welding of closed contacts during short circuit,</tr><tr><tdp><p class="s12">Ag/C 98/2Increase of weld resistance with higher graphite contents, Low contact resistance,</p><p class="s12">GRAPHOR 2Low 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-graphite with vertical orientation has better arc erosion resistance, parallel orientation has better weld resistance,</p></td><td><p class="s12">Motor circuit breakersLimited arc moving properties, therefore paired with Ag/Niother materials,</p></tdp class="s12">Limited formability,<td/p><p class="s12">Contact tipsCan be welded and brazed with decarbonized backing, brazed GRAPHOR DF is optimized for arc erosion resistance and welded contact parts, some contact rivetsweld resistance</p></td></tr><tr/table><td/figtable>  <p classfigtable id="s12tab:tab2.34">Ag/C 97/3<caption>'''<!--Table 2.34:-->Application Examples and Forms of Supply of Silver– Graphite Contact Materials'''</pcaption><p table class="s12twocolortable">GRAPHOR 3<tr></pth><p class="s12">Ag/C 96/4Material</p><p class="s12">GRAPHOR 4</p></th><th><p class="s12">Ag/C 95/5Application Examples</p><p class="s12"/th>GRAPHOR 5</pth><p class="s12">GRAPHOR 3D GRAPHOR 4D GRAPHOR DFForm of Supply</p></tdth></tr><td><p class="s12">Circuit breakers, paired with Cu, Motor-protective circuit breakers, paired with Ag/Ni,C 98/2</p><p class="s12">Fault current circuit breakers, paired with Ag</Ni, Ag/W, Ag/WC, Ag/SnO<span class="s45"p>2</spantd>, Ag/ZnO,</ptd><p class="s12">(Main) Power switchesMotor circuit breakers, 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/C97/3Contact 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">GRAPHOR 3</p><p class="s12">Ag/C 96/4</p><p class="s12">GRAPHOR 4</p><p class="s12">Ag/C 95/5</p><p class="s12">GRAPHOR 5</p><p class="s12">GRAPHOR 3D GRAPHOR 4D GRAPHOR 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">2</span>, Ag/ZnO,</p><p class="s12">(Main) Power switches, paired with Ag/Ni, Ag/W</p></td><td><p class="s12">Contact profiles (weld tapes), Contact tips, brazed and welded contact parts</p></tdp class="s12">parts, some contact rivets with</trp><trp class="s12">Ag/C97/3<td/p></td/></tr></table></figtable>