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Reines Gold ist neben Platin das chemisch beständigste aller Edelmetalle. Gold
in unlegierter Form ist für die Verwendung als Kontaktwerkstoff in elektromechanischen
Bauelementen aufgrund seiner Neigung zum Kleben und Kaltschweißen
auch bei kleinen Kontaktkräften weniger gut geeignet. Außerdem ist Feingold nicht ausreichend mechanisch verschleißfest und widerstandsfähig bei elektrischer
Belastung (<xr id="tab:Contact_and_Switching_Properties_of_Gold_and_Gold_Alloys"/><!--(Tab. 2.4)-->).
Daher beschränkt sich sein Einsatz meist auf dünne, galvanisch
oder vakuumtechnisch aufgebrachte Schichten.
In der Praxis werden daher üblicherweise schmelztechnisch hergestellte Gold-
Legierungen eingesetzt. Der Schmelzvorgang erfolgt dabei je nach Legierungskomponente
in reduzierender Atmosphäre oder im Vakuum. Die Wahl der
Legierungszusätze hängt wesentlich von der Anwendung der Werkstoffe ab.
Aus der breiten Palette von Gold-Legierungen sind die binären Legierungen mit
Zusätzen < 10 Massen-% an Edelmetallen wie Pt, Pd oder Ag bzw. Unedelmetallen
wie Ni, Co, Cu hervorzuheben (<xr id="tab:Physical_Properties_of_Gold_and_Gold_Alloys"/><!--(Tab. 2.2)-->). Diese Zusätze erhöhen einerseits
die mechanische Festigkeit und wirken sich vorteilhaft auf das Schaltverhalten
aus, verringern andererseits je nach Legierungspartner mehr oder weniger
stark die elektrische Leitfähigkeit und die Korrosionsbeständigkeit (<xr id="fig:Influence_of_1_10_atomic_of_different"/><!--(Fig. 2.2)-->).
Vor allem unter dem Aspekt der Goldeinsparung sind die ternären Legierungen
mit Goldgehalten von ca. 70 Massen-% und Zusätzen von Ag und Cu bzw. Ag
und Ni, z.B. AuAg25Cu5 oder AuAg20Cu10 zu sehen, die für viele Anwendungsfälle
bei guten mechanischen Eigenschaften ausreichende Beständigkeit
gegenüber Fremdschichtbildung bieten (<xr id="tab:Mechanical Properties of Gold and Gold-Alloys"/><!--(Table 2.3)-->). Weitere ternäre Legierungen,
die aus dem AuAg-System hervorgehen, sind die Werkstoffe AuAg26Ni3 und
AuAg25Pt6. Diese Legierungen ähneln in ihren mechanischen Eigenschaften
den AuAgCu-Legierungen, sind aber bei höheren Temperaturen deutlich
oxidationsbeständiger.
<figtable id="tab:Commonly Used Grades of Gold">
<caption>'''Überblick über die gebräuchlichsten Gold-Qualitäten'''</caption>
<table class="twocolortable">
<tr><th><p class="s11">Bezeichnung</p></th><th><p class="s11">Zusammensetzung Au</p><p class="s11">(Mindestanteil)</p></th><th><p class="s11">Beimengungen in ppm/p></th><th><p class="s12">Hinweise für die Verwendung</p></th></tr><tr><td><p class="s11">Spektralreines 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">Drähte, Bleche, Legierungszusätze für
Halbleiter, elektronische Bauelemente</p></td></tr><tr><td><p class="s11">Hochreines 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">Granalien für hochreine Legierungen, Bleche, Bänder, Rohre, Profile</p></td></tr><tr><td><p class="s11">Barren-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">Legierungen, übliche Qualität</p></td></tr></table>
</figtable>
<div class="multiple-images">
<figtable id="tab:Physical_Properties_of_Gold_and_Gold_Alloys">
[[File:Physical Properties of Gold and Gold-Alloys.jpg|left|thumb|<caption>Physikalische Eigenschaften von Gold und Goldlegierungen</caption>]]
</figtable>
<figure id="fig:Influence_of_1_10_atomic_of_different">
[[File:Influence of 1-10 atomic of different.jpg|left|thumb|<caption>Einfluss von 1-10 Atom-% verschiedener Zusatzmetalle auf den spez. elektrischen Widerstand p von Gold (nach Linde)</caption>]]
</figure>
</div>
<div class="clear"></div>
<figtable id="tab:Mechanical Properties of Gold and Gold-Alloys">
<caption>'''Festigkeitseigenschaften von Gold und Goldlegierungen'''</caption>
{| class="twocolortable" style="text-align: left; font-size: 12px"
|-
!Werkstoff
!Festigkeitszustand
!Zugfestigkeit Rm [MPa] min.
!Dehnung A<sub>10</sub> [%] min.
!Vickershärte HV
|-
|Au
|R 140<br />R 170<br />R 200<br />R 240
|140<br />170<br />200<br />240
|30<br />3<br />2<br />1
|20<br />50<br />60<br />70
|-
|AuAg20
|R 190<br />R 250<br />R 320<br />R 390
|190<br />250<br />320<br />390
|25<br />2<br />1<br />1
|38<br />70<br />95<br />115
|-
|AuAg30
|R 220<br />R 260<br />R 320<br />R 380
|220<br />260<br />320<br />380
|25<br />3<br />1<br />1
|45<br />75<br />95<br />110
|-
|AuAg25Cu5
|R 400<br />R 470<br />R 570<br />R 700
|400<br />470<br />570<br />700
|25<br />4<br />2<br />2
|90<br />120<br />160<br />185
|-
|AuAg20Cu10
|R 480<br />R 560<br />R 720<br />R 820
|480<br />560<br />720<br />820
|20<br />3<br />1<br />1
|125<br />145<br />190<br />230
|-
|AuAg26Ni3
|R 350<br />R 420<br />R 500<br />R 570
|350<br />420<br />500<br />570
|20<br />2<br />1<br />1
|85<br />110<br />135<br />155
|-
|AuAg25Pt6
|R 280<br />R 330<br />R 410<br />R 480
|280<br />330<br />410<br />480
|18<br />2<br />1<br />1
|60<br />90<br />105<br />125
|-
|AuCo5
|R 340<br />R 390<br />R 450<br />R 530
|340<br />390<br />450<br />530
|10<br />2<br />1<br />1
|95<br />105<br />120<br />150
|-
|AuCo5 prec.hardened
|heterogeneous
|360
|3
|110-130
|-
|AuNi5
|R 380<br />R 450<br />R 560<br />R 640
|380<br />450<br />560<br />640
|25<br />3<br />2<br />1
|115<br />135<br />160<br />190
|-
|AuPt10
|R 260<br />R 310<br />R 370<br />R 410
|260<br />310<br />370<br />410
|20<br />2<br />1<br />1
|80<br />90<br />100<br />105
|-
|AuCu14Pt9Ag4
|R 620<br />R 700<br />R 850<br />R 950<br />prec.hardened
|620<br />700<br />850<br />950<br />900
|20<br />3<br />2<br />1<br />3
|190<br />225<br />260<br />270<br />280
|}
</figtable>
Other ternary alloys based on the AuAg system are AuAg26Ni3 and AuAg25Pt6. These alloys are mechanically similar to the AuAgCu alloys but have significantly higher oxidation resistance at elevated temperatures <xr id="tab:Contact_and_Switching_Properties_of_Gold_and_Gold_Alloys"/><!--(Table 2.4)-->.
<figtable id="tab:Contact_and_Switching_Properties_of_Gold_and_Gold_Alloys">
<caption>'''<!--Table 2.4:-->Contact and Switching Properties of Gold 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,</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 resistance</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, low</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 mechanical</p><p class="s12">wear resistance</p></td></tr></table>
</figtable>
Caused by higher gold prices over the past years the development of alloys with further reduced gold content had a high priority. The starting point has been the AuPd system which has continuous solubility of the two components. Besides the binary alloy of AuPd40 and the ternary one AuPd35Ag9 other multiple component alloys were developed. These alloys typically have < 50 wt% Au and often can be solution hardened in order to obtain even higher hardness and tensile strength. They are mostly used in sliding contact applications.
Gold alloys are used in the form of welded wire or profile (also called weldtapes), segments, contact rivets, and stampings produced from clad strip
materials. The selection of the bonding process is based on the cost for the joining process, and most importantly on the economical aspect of using the least possible amount of the expensive precious metal component.
Besides being used as switching contacts in relays and pushbuttons, gold alloys are also applied in the design of connectors as well as sliding contacts for potentiometers, sensors, slip rings, and brushes in miniature DC motors <xr id="tab:Application Examples and Forms of Gold and Gold Alloys"/><!--(Table 2.5)-->.
<figtable id="tab:Application Examples and Forms of Gold and Gold Alloys">
<caption>'''<!--Table 2.5:-->Application Examples and Forms of Gold and Gold Alloys'''</caption>
<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>
<xr id="fig:Phase diagram of goldplatinum"/> Fig. 2.3: Phase diagram of goldplatinum
<xr id="fig:Phase diagram of gold-silver"/> Fig. 2.4: Phase diagram of gold-silver
<xr id="fig:Phase diagram of gold-copper"/> Fig. 2.5: Phase diagram of gold-copper
<xr id="fig:Phase diagram of gold-nickel"/> Fig. 2.6: Phase diagram of gold-nickel
<xr id="fig:Phase diagram of gold-cobalt"/> Fig. 2.7: Phase diagram of gold-cobalt
<xr id="fig:Strain hardening of Au by cold working"/> Fig. 2.8: Strain hardening of Au by cold working
<xr id="fig:Softening of Au after annealing for 0.5 hrs"/> Fig. 2.9: Softening of Au after annealing for 0.5 hrs after 80% cold working
<xr id="fig:Strain hardening of AuPt10 by cold working"/> Fig. 2.10: Strain hardening of AuPt10 by cold working
<xr id="fig:Strain hardening of AuAg20 by cold working"/> Fig. 2.11: Strain hardening of AuAg20 by cold working
<xr id="fig:Strain hardening of AuAg30 by cold working"/> Fig. 2.12: Strain hardening of AuAg30 by cold working
<xr id="fig:Strain hardening of AuNi5 by cold working"/> Fig. 2.13: Strain hardening of AuNi5 by cold working
<xr id="fig:Softening of AuNi5 after annealing for 0.5 hrs"/> Fig. 2.14: Softening of AuNi5 after annealing for 0.5 hrs after 80% cold working
<xr id="fig:Strain hardening of AuCo5 by cold working"/> Fig. 2.15: Strain hardening of AuCo5 by cold working
<xr id="fig:Precipitation hardening of AuCo5 at"/> Fig. 2.16: Precipitation hardening of AuCo5 at 400°C hardening temperature
<xr id="fig:Strain hardening of AuAg25Pt6 by cold working"/> Fig. 2.17: Strain hardening of AuAg25Pt6 by cold working
<xr id="fig:Strain hardening of AuAg26Ni3 by cold working"/> Fig. 2.18: Strain hardening of AuAg26Ni3 by cold working
<xr id="fig:Softening of AuAg26Ni3 after annealing for 0.5-hrs"/> Fig. 2.19: Softening of AuAg26Ni3 after annealing for 0.5 hrs after 80% cold working
<xr id="fig:Strain hardening of AuAg25Cu5 by cold working"/> Fig. 2.20: Strain hardening of AuAg25Cu5 by cold working
<xr id="fig:Strain hardening of AuAg20Cu10 by cold working"/> Fig. 2.21: Strain hardening of AuAg20Cu10 by cold working
<xr id="fig:Softening of AuAg20Cu10 after annealing for 0.5 hrs"/> Fig. 2.22: Softening of AuAg20Cu10 after annealing for 0.5 hrs after 80% cold working
<xr id="fig:Strain hardening of AuCu14Pt9Ag4 by cold working"/> Fig. 2.23: Strain hardening of AuCu14Pt9Ag4 by cold working
<xr id="fig:Precipitation hardening of AuCu14Pt9Ag4"/> Fig. 2.24: Precipitation hardening of AuCu14Pt9Ag4 at different hardening temperatures after 50% cold working
<div class="multiple-images">
<figure id="fig:Phase diagram of goldplatinum">
[[File:Phase diagram of goldplatinum.jpg|left|thumb|<caption>Phase diagram of goldplatinum</caption>]]
</figure>
<figure id="fig:Phase diagram of gold-silver">
[[File:Phase diagram of gold-silver.jpg|left|thumb|<caption>Phase diagram of gold-silver</caption>]]
</figure>
<figure id="fig:Phase diagram of gold-copper">
[[File:Phase diagram of gold-copper.jpg|left|thumb|<caption>Phase diagram of gold-copper</caption>]]
</figure>
<figure id="fig:Phase diagram of gold-nickel">
[[File:Phase diagram of gold-nickel.jpg|left|thumb|<caption>Phase diagram of gold-nickel</caption>]]
</figure>
<figure id="fig:Phase diagram of gold-cobalt">
[[File:Phase diagram of gold-cobalt.jpg|left|thumb|<caption>Phase diagram of gold-cobalt</caption>]]
</figure>
<figure id="fig:Strain 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:Softening of Au after annealing for 0.5 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:Strain 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:Strain 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:Strain 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:Strain 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:Softening of AuNi5 after annealing for 0.5 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:Strain 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:Precipitation 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:Strain 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:Strain 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:Softening of AuAg26Ni3 after annealing for 0.5-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:Strain 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:Strain 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:Softening of AuAg20Cu10 after annealing for 0.5 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:Strain 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:Precipitation 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>
<div class="clear"></div>
==Referenzen==
[[Kontaktwerkstoffe_für_die_Elektrotechnik#Referenzen|Referenzen]]
[[en:Gold_Based_Materials]]
in unlegierter Form ist für die Verwendung als Kontaktwerkstoff in elektromechanischen
Bauelementen aufgrund seiner Neigung zum Kleben und Kaltschweißen
auch bei kleinen Kontaktkräften weniger gut geeignet. Außerdem ist Feingold nicht ausreichend mechanisch verschleißfest und widerstandsfähig bei elektrischer
Belastung (<xr id="tab:Contact_and_Switching_Properties_of_Gold_and_Gold_Alloys"/><!--(Tab. 2.4)-->).
Daher beschränkt sich sein Einsatz meist auf dünne, galvanisch
oder vakuumtechnisch aufgebrachte Schichten.
In der Praxis werden daher üblicherweise schmelztechnisch hergestellte Gold-
Legierungen eingesetzt. Der Schmelzvorgang erfolgt dabei je nach Legierungskomponente
in reduzierender Atmosphäre oder im Vakuum. Die Wahl der
Legierungszusätze hängt wesentlich von der Anwendung der Werkstoffe ab.
Aus der breiten Palette von Gold-Legierungen sind die binären Legierungen mit
Zusätzen < 10 Massen-% an Edelmetallen wie Pt, Pd oder Ag bzw. Unedelmetallen
wie Ni, Co, Cu hervorzuheben (<xr id="tab:Physical_Properties_of_Gold_and_Gold_Alloys"/><!--(Tab. 2.2)-->). Diese Zusätze erhöhen einerseits
die mechanische Festigkeit und wirken sich vorteilhaft auf das Schaltverhalten
aus, verringern andererseits je nach Legierungspartner mehr oder weniger
stark die elektrische Leitfähigkeit und die Korrosionsbeständigkeit (<xr id="fig:Influence_of_1_10_atomic_of_different"/><!--(Fig. 2.2)-->).
Vor allem unter dem Aspekt der Goldeinsparung sind die ternären Legierungen
mit Goldgehalten von ca. 70 Massen-% und Zusätzen von Ag und Cu bzw. Ag
und Ni, z.B. AuAg25Cu5 oder AuAg20Cu10 zu sehen, die für viele Anwendungsfälle
bei guten mechanischen Eigenschaften ausreichende Beständigkeit
gegenüber Fremdschichtbildung bieten (<xr id="tab:Mechanical Properties of Gold and Gold-Alloys"/><!--(Table 2.3)-->). Weitere ternäre Legierungen,
die aus dem AuAg-System hervorgehen, sind die Werkstoffe AuAg26Ni3 und
AuAg25Pt6. Diese Legierungen ähneln in ihren mechanischen Eigenschaften
den AuAgCu-Legierungen, sind aber bei höheren Temperaturen deutlich
oxidationsbeständiger.
<figtable id="tab:Commonly Used Grades of Gold">
<caption>'''Überblick über die gebräuchlichsten Gold-Qualitäten'''</caption>
<table class="twocolortable">
<tr><th><p class="s11">Bezeichnung</p></th><th><p class="s11">Zusammensetzung Au</p><p class="s11">(Mindestanteil)</p></th><th><p class="s11">Beimengungen in ppm/p></th><th><p class="s12">Hinweise für die Verwendung</p></th></tr><tr><td><p class="s11">Spektralreines 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">Drähte, Bleche, Legierungszusätze für
Halbleiter, elektronische Bauelemente</p></td></tr><tr><td><p class="s11">Hochreines 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">Granalien für hochreine Legierungen, Bleche, Bänder, Rohre, Profile</p></td></tr><tr><td><p class="s11">Barren-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">Legierungen, übliche Qualität</p></td></tr></table>
</figtable>
<div class="multiple-images">
<figtable id="tab:Physical_Properties_of_Gold_and_Gold_Alloys">
[[File:Physical Properties of Gold and Gold-Alloys.jpg|left|thumb|<caption>Physikalische Eigenschaften von Gold und Goldlegierungen</caption>]]
</figtable>
<figure id="fig:Influence_of_1_10_atomic_of_different">
[[File:Influence of 1-10 atomic of different.jpg|left|thumb|<caption>Einfluss von 1-10 Atom-% verschiedener Zusatzmetalle auf den spez. elektrischen Widerstand p von Gold (nach Linde)</caption>]]
</figure>
</div>
<div class="clear"></div>
<figtable id="tab:Mechanical Properties of Gold and Gold-Alloys">
<caption>'''Festigkeitseigenschaften von Gold und Goldlegierungen'''</caption>
{| class="twocolortable" style="text-align: left; font-size: 12px"
|-
!Werkstoff
!Festigkeitszustand
!Zugfestigkeit Rm [MPa] min.
!Dehnung A<sub>10</sub> [%] min.
!Vickershärte HV
|-
|Au
|R 140<br />R 170<br />R 200<br />R 240
|140<br />170<br />200<br />240
|30<br />3<br />2<br />1
|20<br />50<br />60<br />70
|-
|AuAg20
|R 190<br />R 250<br />R 320<br />R 390
|190<br />250<br />320<br />390
|25<br />2<br />1<br />1
|38<br />70<br />95<br />115
|-
|AuAg30
|R 220<br />R 260<br />R 320<br />R 380
|220<br />260<br />320<br />380
|25<br />3<br />1<br />1
|45<br />75<br />95<br />110
|-
|AuAg25Cu5
|R 400<br />R 470<br />R 570<br />R 700
|400<br />470<br />570<br />700
|25<br />4<br />2<br />2
|90<br />120<br />160<br />185
|-
|AuAg20Cu10
|R 480<br />R 560<br />R 720<br />R 820
|480<br />560<br />720<br />820
|20<br />3<br />1<br />1
|125<br />145<br />190<br />230
|-
|AuAg26Ni3
|R 350<br />R 420<br />R 500<br />R 570
|350<br />420<br />500<br />570
|20<br />2<br />1<br />1
|85<br />110<br />135<br />155
|-
|AuAg25Pt6
|R 280<br />R 330<br />R 410<br />R 480
|280<br />330<br />410<br />480
|18<br />2<br />1<br />1
|60<br />90<br />105<br />125
|-
|AuCo5
|R 340<br />R 390<br />R 450<br />R 530
|340<br />390<br />450<br />530
|10<br />2<br />1<br />1
|95<br />105<br />120<br />150
|-
|AuCo5 prec.hardened
|heterogeneous
|360
|3
|110-130
|-
|AuNi5
|R 380<br />R 450<br />R 560<br />R 640
|380<br />450<br />560<br />640
|25<br />3<br />2<br />1
|115<br />135<br />160<br />190
|-
|AuPt10
|R 260<br />R 310<br />R 370<br />R 410
|260<br />310<br />370<br />410
|20<br />2<br />1<br />1
|80<br />90<br />100<br />105
|-
|AuCu14Pt9Ag4
|R 620<br />R 700<br />R 850<br />R 950<br />prec.hardened
|620<br />700<br />850<br />950<br />900
|20<br />3<br />2<br />1<br />3
|190<br />225<br />260<br />270<br />280
|}
</figtable>
Other ternary alloys based on the AuAg system are AuAg26Ni3 and AuAg25Pt6. These alloys are mechanically similar to the AuAgCu alloys but have significantly higher oxidation resistance at elevated temperatures <xr id="tab:Contact_and_Switching_Properties_of_Gold_and_Gold_Alloys"/><!--(Table 2.4)-->.
<figtable id="tab:Contact_and_Switching_Properties_of_Gold_and_Gold_Alloys">
<caption>'''<!--Table 2.4:-->Contact and Switching Properties of Gold 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,</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 resistance</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, low</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 mechanical</p><p class="s12">wear resistance</p></td></tr></table>
</figtable>
Caused by higher gold prices over the past years the development of alloys with further reduced gold content had a high priority. The starting point has been the AuPd system which has continuous solubility of the two components. Besides the binary alloy of AuPd40 and the ternary one AuPd35Ag9 other multiple component alloys were developed. These alloys typically have < 50 wt% Au and often can be solution hardened in order to obtain even higher hardness and tensile strength. They are mostly used in sliding contact applications.
Gold alloys are used in the form of welded wire or profile (also called weldtapes), segments, contact rivets, and stampings produced from clad strip
materials. The selection of the bonding process is based on the cost for the joining process, and most importantly on the economical aspect of using the least possible amount of the expensive precious metal component.
Besides being used as switching contacts in relays and pushbuttons, gold alloys are also applied in the design of connectors as well as sliding contacts for potentiometers, sensors, slip rings, and brushes in miniature DC motors <xr id="tab:Application Examples and Forms of Gold and Gold Alloys"/><!--(Table 2.5)-->.
<figtable id="tab:Application Examples and Forms of Gold and Gold Alloys">
<caption>'''<!--Table 2.5:-->Application Examples and Forms of Gold and Gold Alloys'''</caption>
<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>
<xr id="fig:Phase diagram of goldplatinum"/> Fig. 2.3: Phase diagram of goldplatinum
<xr id="fig:Phase diagram of gold-silver"/> Fig. 2.4: Phase diagram of gold-silver
<xr id="fig:Phase diagram of gold-copper"/> Fig. 2.5: Phase diagram of gold-copper
<xr id="fig:Phase diagram of gold-nickel"/> Fig. 2.6: Phase diagram of gold-nickel
<xr id="fig:Phase diagram of gold-cobalt"/> Fig. 2.7: Phase diagram of gold-cobalt
<xr id="fig:Strain hardening of Au by cold working"/> Fig. 2.8: Strain hardening of Au by cold working
<xr id="fig:Softening of Au after annealing for 0.5 hrs"/> Fig. 2.9: Softening of Au after annealing for 0.5 hrs after 80% cold working
<xr id="fig:Strain hardening of AuPt10 by cold working"/> Fig. 2.10: Strain hardening of AuPt10 by cold working
<xr id="fig:Strain hardening of AuAg20 by cold working"/> Fig. 2.11: Strain hardening of AuAg20 by cold working
<xr id="fig:Strain hardening of AuAg30 by cold working"/> Fig. 2.12: Strain hardening of AuAg30 by cold working
<xr id="fig:Strain hardening of AuNi5 by cold working"/> Fig. 2.13: Strain hardening of AuNi5 by cold working
<xr id="fig:Softening of AuNi5 after annealing for 0.5 hrs"/> Fig. 2.14: Softening of AuNi5 after annealing for 0.5 hrs after 80% cold working
<xr id="fig:Strain hardening of AuCo5 by cold working"/> Fig. 2.15: Strain hardening of AuCo5 by cold working
<xr id="fig:Precipitation hardening of AuCo5 at"/> Fig. 2.16: Precipitation hardening of AuCo5 at 400°C hardening temperature
<xr id="fig:Strain hardening of AuAg25Pt6 by cold working"/> Fig. 2.17: Strain hardening of AuAg25Pt6 by cold working
<xr id="fig:Strain hardening of AuAg26Ni3 by cold working"/> Fig. 2.18: Strain hardening of AuAg26Ni3 by cold working
<xr id="fig:Softening of AuAg26Ni3 after annealing for 0.5-hrs"/> Fig. 2.19: Softening of AuAg26Ni3 after annealing for 0.5 hrs after 80% cold working
<xr id="fig:Strain hardening of AuAg25Cu5 by cold working"/> Fig. 2.20: Strain hardening of AuAg25Cu5 by cold working
<xr id="fig:Strain hardening of AuAg20Cu10 by cold working"/> Fig. 2.21: Strain hardening of AuAg20Cu10 by cold working
<xr id="fig:Softening of AuAg20Cu10 after annealing for 0.5 hrs"/> Fig. 2.22: Softening of AuAg20Cu10 after annealing for 0.5 hrs after 80% cold working
<xr id="fig:Strain hardening of AuCu14Pt9Ag4 by cold working"/> Fig. 2.23: Strain hardening of AuCu14Pt9Ag4 by cold working
<xr id="fig:Precipitation hardening of AuCu14Pt9Ag4"/> Fig. 2.24: Precipitation hardening of AuCu14Pt9Ag4 at different hardening temperatures after 50% cold working
<div class="multiple-images">
<figure id="fig:Phase diagram of goldplatinum">
[[File:Phase diagram of goldplatinum.jpg|left|thumb|<caption>Phase diagram of goldplatinum</caption>]]
</figure>
<figure id="fig:Phase diagram of gold-silver">
[[File:Phase diagram of gold-silver.jpg|left|thumb|<caption>Phase diagram of gold-silver</caption>]]
</figure>
<figure id="fig:Phase diagram of gold-copper">
[[File:Phase diagram of gold-copper.jpg|left|thumb|<caption>Phase diagram of gold-copper</caption>]]
</figure>
<figure id="fig:Phase diagram of gold-nickel">
[[File:Phase diagram of gold-nickel.jpg|left|thumb|<caption>Phase diagram of gold-nickel</caption>]]
</figure>
<figure id="fig:Phase diagram of gold-cobalt">
[[File:Phase diagram of gold-cobalt.jpg|left|thumb|<caption>Phase diagram of gold-cobalt</caption>]]
</figure>
<figure id="fig:Strain 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:Softening of Au after annealing for 0.5 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:Strain 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:Strain 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:Strain 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:Strain 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:Softening of AuNi5 after annealing for 0.5 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:Strain 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:Precipitation 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:Strain 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:Strain 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:Softening of AuAg26Ni3 after annealing for 0.5-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:Strain 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:Strain 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:Softening of AuAg20Cu10 after annealing for 0.5 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:Strain 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:Precipitation 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>
<div class="clear"></div>
==Referenzen==
[[Kontaktwerkstoffe_für_die_Elektrotechnik#Referenzen|Referenzen]]
[[en:Gold_Based_Materials]]
