2,315
edits
Changes
no edit summary
For most electrical contact applications, gold alloys are used. Depending on the alloying metal, the melting is performed either under a reducing atmosphere or in a vacuum. The choice of alloying metals depends on the intended use of the resulting contact material. The binary Au alloys with typically < 10 wt% of other precious metals such as Pt, Pd, Ag or non-precious metals like Ni, Co and Cu are the more commonly used ones (<xr id="tab:Physical Properties of Gold and Gold-Alloys"/>)<!--(Tab. 2.2)-->.
On one hand these alloy additions improve the mechanical strength and electrical switching properties but on the other hand reduce the electrical conductivity and chemical corrosion resistance (<xr id="fig:Influence_of_1_10_atomic_of_different"/>)<!--(Fig. 2.2)--> to varying degrees.
Under the aspect of reducing the gold content , ternary alloys with a gold content of approximately 70 wt% and additions of Ag and Cu or Ag and Ni resp., for example AuAg25Cu5 or AuAg20Cu10 are used , which exhibit for many applications good mechanical stability , while at the same time have sufficientresistance against the formation of corrosion layers (<xr id="tab:tab2Mechanical Properties of Gold and Gold-Alloys"/>)<!--(Table 2.3)-->. <figtable id="tab:Commonly Used Grades of Gold"/><caption>'''Commonly Used Grades of Gold<!--(Table 2.1)-->'''</caption><table class="twocolortable"> <tr><th><p class="s11">Designation</p></th><th><p class="s11">Composition Au</p><p class="s11">(min. content)</p></th><th><p class="s11">Impurites ppm</p></th><th><p class="s12">Remarks on forms and application</p></th></tr><tr><td><p class="s11">Electronic Gold</p><p class="s11">Gold</p></td><td><p class="s11">99.999</p></td><td><p class="s11">Cu < 3</p><p class="s11">Ag < 3)</p><p class="s11">Ca < 1</p><p class="s11">Mg <1</p><p class="s11">Fe < 1</p></td><td><p class="s12">Wires, strips, alloying metal for semiconductors, electronic components</p></td></tr><tr><td><p class="s11">Pure Gold</p></td><td><p class="s11">99.995</p></td><td><p class="s11">Cu < 10</p><p class="s11">Ag < 15</p><p class="s11">Ca < 20</p><p class="s11">Mg < 10</p><p class="s11">Fe < 3</p><p class="s11">Si < 10</p><p class="s11">Pb < 20</p></td><td><p class="s12">Granulate for high purity alloys, strips, tubing, profiles</p></td></tr><tr><td><p class="s11">Ingot Grade-Gold</p></td><td><p class="s11">99.95</p></td><td><p class="s11">Cu < 100</p><p class="s11">Ag < 150</p><p class="s11">Ca < 50</p><p class="s11">Mg < 50</p><p class="s11">Fe < 30</p><p class="s11">Si < 10</p></td><td><p class="s12">Alloys, commonly used grade</p></td></tr></table></figtable><br/><br/> <figtable id="tab:Physical Properties of Gold and Gold-Alloys"><caption>'''Physical Properties of Gold and Gold-Alloys'''</caption> {| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material!Gold<br/>Content<br/>[wt.%]!Density<br/>[g/cm<sup>3</sup>]!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. Coeff. of<br/>the electr. Resistance<br/>[10<sup>-3<sup/>/K]!Modulus of<br/>Elasticity<br/>[GPa]|-|Au (99,95)| >99,95|19,3|1064|2,32|43|317|4,0|79|-|AuAg8|92|18,1|1058|6,13|16,3|147|1,25|82|-|AuAg20|80|16,4|1035 - 1045|10,0|10|75|0,86|89|-|AuNi5|95|18,3|995 - 1018|13,5|7,4|53|0,71|83|-|AuCo5|95|18,2|1010 - 1015|55,6|1,8||0,68|88|-|AuCo5 (het.)|95|18,2|1010 - 1015|5,99|16,7||||-|AuAg25Cu5|70|15,2|950 - 980|12,2|8,2||0,75|89|-|AuAg20C10|70|15,1|865 - 895|13,3|7,5|66|0,52|87|-|AuAg26Ni3|71|15,4|990 - 1020|11,0|9,1|59|0,88|114|-|AuPt10|90|19,5|1150 - 1190|12,5|8,0|54|||-|AuAg25Pt6|69|16,1|1060|15,9|6,3|46|0,54|93|-|AuCu14Pt9Ag4|73|16,0|955|14,3 - 25|4 - 7||||-|}</figtable>
<div class="multiple-images">
</figure>
</div>
<div class="clear"></div>
<figtable id="tab:Mechanical Properties of Gold and Gold-Alloys"><caption>'''<!--Tab.2.3: -->Mechanical Properties of Gold and Gold-Alloys'''<figtable id="tab:tab2.3"/caption>
{| class="twocolortable" style="text-align: left; font-size: 12px"
|-
|}
</figtable>
<figtable id="tab:Contact_and_Switching_Properties_of_Gold_and_Gold_Alloys"><caption>'''<!--Table 2.4:-->Contact and Switching Properties of Gold alloys are used in the form of welded wire or profile (also called weldtapes)and Gold Alloys'''</caption><table class="twocolortable"> <tr><th><p class="s11">Material</p></th><th><p class="s12">Properties<th colspan="2"></p></th></tr><tr><td><p class="s11">Au</p></td><td><p class="s12">Highest corrosion resistance, low</p><p class="s12">hardness</p></td><td><p class="s12">High electr. conductivity, segments</p><p class="s12">strong tendency to cold welding</p></td></tr><tr><td><p class="s11">AuAg8</p></td><td><p class="s12">High corrosion resistance, low thermo</p><p class="s12">e.m.f.</p></td><td><p class="s12">Low contact rivetsresistance</p></td></tr><tr><td><p class="s11">AuPt10</p><p class="s11">AuPd5</p></td><td><p class="s12">Very high corrosion resistance</p></td><td><p class="s12">High hardness</p></td></tr><tr><td><p class="s11">AuAg10 - 30</p></td><td><p class="s12">Mostly corrosion resistant</p></td><td><p class="s12">Higher hardness</p></td></tr><tr><td><p class="s11">AuNi5</p><p class="s11">AuCo5</p></td><td><p class="s12">High corrosion resistance, and stampings produced from clad stripmaterials. The selection of the bonding process is based on the cost for the joining processlow</p><p class="s12">tendency to material transfer</p></td><td><p class="s12">High hardness</p></td></tr><tr><td><p class="s11">AuAg25Pt6</p></td><td><p class="s12">High corrosion resistance, low contact resistance</p></td><td><p class="s12">High hardness</p></td></tr><tr><td><p class="s11">AuAg26Ni3</p><p class="s11">AuAg25Cu5</p><p class="s11">AuAg20Cu10</p></td><td><p class="s12">Limited corrosion resistance</p></td><td><p class="s12">High hardness</p></td></tr><tr><td><p class="s11">AuPd40</p><p class="s11">AuPd35Ag10</p><p class="s11">AuCu14Pt9Ag4</p></td><td><p class="s12">High corrosion resistance</p></td><td><p class="s12">High hardness and most importantly on the economical aspect of using themechanical</p><p class="s12">wear resistance</p></td></tr></table>least possible amount of the expensive precious metal component.</figtable>
<table class="twocolortable">
<tr><th><p class="s11">Material</p></th><th><p class="s12">Application Examples</p></th><th><p class="s12">Form of Application</p></th></tr><tr><td><p class="s11">Pure Gold</p><p class="s11">(electroplated)</p></td><td><p class="s12">Corrosion protection layer for contact parts, stationary contacts, bonding surfaces</p></td><td><p class="s12">Electroplated coatings, bond surface layers</p></td></tr><tr><td><p class="s11">Hard Gold</p><p class="s11">(sputtered)</p></td><td><p class="s12">Contact parts for connectors and switches, sliding contact tracks, bonding surfaces</p></td><td><p class="s12">Electroplated coatings on contact rivets and stamped parts</p></td></tr><tr><td><p class="s11">Hard Gold</p><p class="s11">(sputtered)</p></td><td><p class="s12">Contacts in switches and relays for low loads, electronic signal relays</p></td><td><p class="s12">Contact surface layer on miniature</p><p class="s12">profiles (weld tapes)</p></td></tr><tr><td><p class="s11">AuAg8</p></td><td><p class="s12">Dry circuit switching contacts, electronic</p><p class="s12">signal relays</p></td><td><p class="s12">Contact rivets, welded contact</p><p class="s12">parts</p></td></tr><tr><td><p class="s11">AuAg20</p></td><td><p class="s12">Switching contacts for low loads, electronic</p><p class="s12">signal relays</p></td><td><p class="s12">Contact rivets, welded contact</p><p class="s12">parts</p></td></tr><tr><td><p class="s11">AuAg25Cu5</p><p class="s11">AuAg25Cu10</p><p class="s11">AuAg26Ni3</p></td><td><p class="s12">Contact parts for connectors, switches and relays</p></td><td><p class="s12">Claddings on Cu alloys, contact rivets, contact layer on micro profiles (weld tapes)</p></td></tr><tr><td><p class="s11">AuNi5</p><p class="s11">AuCo5 (heterogen)</p></td><td><p class="s12">Contacts in switches and relays for low and medium loads, material transfer resistant contacts</p></td><td><p class="s12">Contact rivets, welded contact parts, contact layer on miniature profiles (weld tapes)</p></td></tr><tr><td><p class="s11">AuPt10</p><p class="s11">AuAg25Pt6</p></td><td><p class="s12">Contacts for highest chemical corrosion resistance in switches and relays</p></td><td><p class="s12">Contact rivets, contact layer on micro profiles (weld tapes)</p></td></tr><tr><td><p class="s11">AuCu14Pt9Ag4</p></td><td><p class="s12">Sliding contacts for measurement data transfer</p></td><td><p class="s12">Wire-formed parts</p></td></tr></table>
</figtable>
<div class="multiple-images">
<figure id="fig:fig2.3Phase diagram of goldplatinum">[[File:Phase diagram of goldplatinum.jpg|left|thumb|<caption>Phase diagram of goldplatinum</caption>]]
</figure>
<figure id="fig:fig2.4Phase diagram of gold-silver">[[File:Phase diagram of gold-silver.jpg|left|thumb|<caption>Phase diagram of gold-silver</caption>]]
</figure>
<figure id="fig:fig2.5Phase diagram of gold-copper">[[File:Phase diagram of gold-copper.jpg|left|thumb|<caption>Phase diagram of gold-copper</caption>]]
</figure>
<figure id="fig:fig2.6Phase diagram of gold-nickel">[[File:Phase diagram of gold-nickel.jpg|left|thumb|<caption>Phase diagram of gold-nickel</caption>]]
</figure>
<figure id="fig:fig2.7Phase diagram of gold-cobalt">[[File:Phase diagram of gold-cobalt.jpg|left|thumb|<caption>Phase diagram of gold-cobalt</caption>]]
</figure>
<figure id="fig:fig2.8Strain hardening of Au by cold working">[[File:Strain hardening of Au by cold working.jpg|left|thumb|<caption>Strain hardening of Au by cold working</caption>]]
</figure>
<figure id="fig:fig2Softening of Au after annealing for 0.95 hrs">[[File:Softening of Au after annealing for 0.5 hrs.jpg|left|thumb|<caption>Softening of Au after annealing for 0.5 hrs after 80% cold working</caption>]]
</figure>
<figure id="fig:fig2.10Strain hardening of AuPt10 by cold working">[[File:Strain hardening of AuPt10 by cold working.jpg|left|thumb|<caption>Strain hardening of AuPt10 by cold working</caption>]]
</figure>
<figure id="fig:fig2.11Strain hardening of AuAg20 by cold working">[[File:Strain hardening of AuAg20 by cold working.jpg|left|thumb|<caption>Strain hardening of AuAg20 by cold working</caption>]]
</figure>
<figure id="fig:fig2.12Strain hardening of AuAg30 by cold working">[[File:Strain hardening of AuAg30 by cold working.jpg|left|thumb|<caption>Strain hardening of AuAg30 by cold working</caption>]]
</figure>
<figure id="fig:fig2.13Strain hardening of AuNi5 by cold working">[[File:Strain hardening of AuNi5 by cold working.jpg|left|thumb|<caption>Strain hardening of AuNi5 by cold working</caption>]]
</figure>
<figure id="fig:fig2Softening of AuNi5 after annealing for 0.145 hrs">[[File:Softening of AuNi5 after annealing for 0.5 hrs.jpg|left|thumb|<caption>Softening of AuNi5 after annealing for 0.5 hrs after 80% cold working</caption>]]
</figure>
<figure id="fig:fig2.15Strain hardening of AuCo5 by cold working">[[File:Strain hardening of AuCo5 by cold working.jpg|left|thumb|<caption>Strain hardening of AuCo5 by cold working</caption>]]
</figure>
<figure id="fig:fig2.16Precipitation hardening of AuCo5 at">[[File:Precipitation hardening of AuCo5 at.jpg|left|thumb|<caption>Precipitation hardening of AuCo5 at 400°C hardening temperature</caption>]]
</figure>
<figure id="fig:fig2.17Strain hardening of AuAg25Pt6 by cold working">[[File:Strain hardening of AuAg25Pt6 by cold working.jpg|left|thumb|<caption>Strain hardening of AuAg25Pt6 by cold working</caption>]]
</figure>
<figure id="fig:fig2.18Strain hardening of AuAg26Ni3 by cold working">[[File:Strain hardening of AuAg26Ni3 by cold working.jpg|left|thumb|<caption>Strain hardening of AuAg26Ni3 by cold working</caption>]]
</figure>
<figure id="fig:fig2Softening of AuAg26Ni3 after annealing for 0.195-hrs">[[File:Softening of AuAg26Ni3 after annealing for 0.5-hrs.jpg|left|thumb|<caption>Softening of AuAg26Ni3 after annealing for 0.5 hrs after 80% cold working</caption>]]
</figure>
<figure id="fig:fig2.20Strain hardening of AuAg25Cu5 by cold working">[[File:Strain hardening of AuAg25Cu5 by cold working.jpg|left|thumb|<caption>Strain hardening of AuAg25Cu5 by cold working</caption>]]
</figure>
<figure id="fig:fig2.21Strain hardening of AuAg20Cu10 by cold working">[[File:Strain hardening of AuAg20Cu10 by cold working.jpg|left|thumb|<caption>Strain hardening of AuAg20Cu10 by cold working</caption>]]
</figure>
<figure id="fig:fig2Softening of AuAg20Cu10 after annealing for 0.225 hrs">[[File:Softening of AuAg20Cu10 after annealing for 0.5 hrs.jpg|left|thumb|<caption>Softening of AuAg20Cu10 after annealing for 0.5 hrs after 80% cold working</caption>]]
</figure>
<figure id="fig:fig2.23Strain hardening of AuCu14Pt9Ag4 by cold working">[[File:Strain hardening of AuCu14Pt9Ag4 by cold working.jpg|left|thumb|<caption>Strain hardening of AuCu14Pt9Ag4 by cold working</caption>]]
</figure>
<figure id="fig:fig2.24Precipitation hardening of AuCu14Pt9Ag4">[[File:Precipitation hardening of AuCu14Pt9Ag4.jpg|left|thumb|<caption>Precipitation hardening of AuCu14Pt9Ag4 at different hardening temperatures after 50% cold working</caption>]]
</figure>
</div>
==References==
[[Contact Materials for Electrical Engineering#References|References]]
[[de:Werkstoffe_auf_Gold-Basis]]