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Rhodium is not used as a solid contact material but is applied for example as a electroplated layer in sliding contact systems. Ruthenium is mostly used as an alloying component in the material PdRu15. The metals osmium and iridium have no practical applications in electrical contacts.
Since Pd was for the longest time rather stable in price, it was seen as a substitute for the more expensive gold. This was followed by a steep increase in the Pd price, which caused a significant reduction in its use in electrical contacts. Today (2011Dec. 2021) the Pd palladium price again is lower than that of goldaround 2600 Euro/oz.
Alloys of Pt with Ru, Ir, Ni and W were widely used in electromechanical components in the telecommunication industry and in heavy duty automotive breaker points (<xr id="tab:Physikalische Eigenschaften von Platin-Metallen und deren LegierungenPhysical Properties of the Platinum Metals an their Alloys/>).
<figtable id="tab:Physikalische Eigenschaften von Platin-Metallen und deren LegierungenPhysical Properties of the Platinum Metals an their Alloys"><caption>'''<!--Table 2.7:-->Physikalische Eigenschaften von Platin-Metallen und deren LegierungenPhysical Properties of the Platinum Metals an their Alloys'''</caption>
{| class="twocolortable" style="text-align: left; font-size: 12px"
|-
!Material
!Platin/Palladium<br/>AnteilContent<br/>[gewwt.-%]!DichteDensity<br/>[g/cm<sup>3</sup>]!Schmelzpunkt oder<br/>SchmelzbereichMelting Point or Range<br/>[°C]!ElekrischeElectrical<br/>Resistivity<br/>Widerstandskraft[µΩ*cm]!ElektrischeElectrical<br/>LeitfähigkeitConductivity<br/>[MS/m]!ThermischeThermal<br/>LeitfähigkeitConductivity<br/>[W/m*K]!Temperaturkoeffizient desTemp. Coefficient of the<br/>elektrischen WiderstandsElectrical Resistance<br/>[10<sup>3</sup>/K]!Elastizitätsmodulmodulus of<br/>Elasticity<br/>[Gpa]
|-
|Pt (99,95)
</figtable>
Today these components have been replaced in many applications by solid state technology and the usage of these materials is greatly reduced. Pd alloys however have a more significant importance. PdCu15 is widely used, for example in automotive flasher relays. Because of their resistance to sulfide formation PdAg alloys are applied in various relay designs. With the ability to thermally precipitation harden some multi component alloys based on PdAgAuPt, they find special usage in wear resistant sliding contact applications. Pd44Ag38Cu15PtAuZn is a standard alloy in this group (<xr id="tab:Mechanical_Properties_of_the_Platinum_Metals_and_their_Alloys"/><!--(Tab 2.8)--> and <xr id="tab:Contact_and_Switching_Properties_of_the_Platinum_Metals_and_their_Alloys"/><!--(Tab. 2.9)-->).