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<figtable id="tab:tab2.2">
[[File:Physical Properties of Gold and Gold-Alloys.jpg|right|thumb|<caption>Tab 2.2 Physical Properties of Gold and Gold-Alloys</caption>]]
</figtable>
<figure id="fig:fig2.2">
[[File:Influence of 1-10 atomic of different.jpg|right|thumb|<caption>Fig 2.2 Influence of 1-10 atomic% of different alloying metals on the electrical resistivity of gold (according to J. O. Linde)</caption>]]
</figure>
Pure Gold is besides Platinum the chemically most stable of all precious metals. In its pure form it is not very suitable for use as a contact material in electromechanical devices because of its tendency to stick and cold-weld at even low contact forces. In addition it is not hard or strong enough to resist mechanical wear and exhibits high materials losses under electrical arcing loads. This limits its use in form of thin electroplated or vacuum deposited layers.
For most electrical contact applications gold alloys are used. Depending on the alloying metal the melting is performed either under in 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, or Ag or non-precious metals like Ni, Co, and Cu are the more commonly used ones <xr id="tab:tab2.2"/> ''(Table 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:fig2.2"/>''(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 sufficient
