Changes

The platinum group metals include the elements Pt, Pd, Rh, Ru, Ir, and Os <xr id="figtab:Properties_Production_Processes,_and_Application_Forms_for_Platinum Metalstab2.6"/> (Tab. 2.6). For electrical contacts platinum and palladium have practical significance as base alloy materials and ruthenium and iridium are used as alloying components. Pt and Pd have similar corrosion resistance as gold but because of their catalytical properties they tend to polymerize adsorbed organic vapors on contact surfaces. During frictional movement between contact surfaces the polymerized compounds known as “brown powder” are formed which can lead to significantly increase in contact resistance. Therefore Pt and Pd are typically used as alloys and not in their pure form for electrical contact applications.  <figtable id="tab:tab2.6">'''Table 2.16: Application Examples and Forms of Supply for Silver and Silver Alloys''' {| class="twocolortable" style="text-align: left; font-size: 12px"|-!Element !Properties!Processing!Forms of Application|-|Ru<br />Ruthenium|Dull grey to silvery white, very hard and brittle,<br />in the presence of oxygen resistant to acids,<br />oxidizes during heating in air|Vapor deposition, sputtering, powder metallurgy,<br />warm-forming only possible at 1200 – 1500°C|Powder; in sheet form, as coatings,<br />and as wire mostly as alloying component|-|Rh<br />Rhodium |Almost silvery white, very hard and brittle, not soluble in acids,<br />oxidizes in air during red anneal|Electroplating, vapor deposition, sputtering,<br />after warm-forming at 800 – 1000°C cold working is possible|Coatings (electroplated), alloying component,<br />in limited form as sheet and wire|-|Pd<br />Palladium|Dull white, resistant to most acids,<br />oxidizes at red anneal|Electroplating, vapor deposition,<br />sputtering, cold working|Sheet, strip, tubing,<br />wire, rivets, and coatings|}</figtable>