What precious metals are used in electroplating?
Precious metals commonly used in electroplating and surface finishing operations include gold, silver, indium, ruthenium, palladium and rhodium. Factors that influence the selection of precious metals are their contact characteristics, corrosion resistance, heat resistance, reflectivity, solderability, color and wear resistance. Silver has an advantage of its relative low cost, but it is susceptible to tarnishing when exposed to sulfur in the atmosphere. Gold has excellent solderability and electrical characteristics. The hardness and appearance of gold can be modified with different alloying elements. Indium is a precious metal that has the unique quality of cold fusing at room temperature with aluminum and copper. This cold welded bond keeps out oxidation between the indium plated part and the aluminum or copper base material allowing for excellent electrical and thermal transfer contacts. This coating is the UL approved finish for connecting aluminum wiring to a copper receptacle.
