Powder Metallurgy Electrical Contact Materials^[1]

Electrical contacts are made of elemental metals, composites, or alloys that are made by the melt-cast method or manufactured by powder metallurgy (PM) processes. PM facilitates combinations of metals that ordinarily cannot be achieved by alloying. This article describes the processing, properties, and performance of electrical contacts based on PM or hybrid composite technologies with refractory metals and compounds. These metals and compounds include tungsten, molybdenum, carbide-based composites, and silver-base composites. The article explains composite manufacturing methods, namely, PM methods, internal oxidation, and hybrid consolidation. The availability of the refractory metals and compounds in various product forms are also reviewed.