Composite Materials: This compromise of two or more metals which are indissoluble even in liquid state or mixtures of metals with nonmetallic substances such as oxides and other refractory materials. Examples are:
(a) Electrical contact material (such as tungsten/copper or silver/cadmium oxide)
(b) Hard metals (cemented carbides) used for cutting tools and wearing parts.
Tungsten carbide bonded with cobalt was the first of this class of material and still has the main part of the market, but other carbides and nitrides, carbonitride and borides are used in increasing quantities and instead of the expensive cobalt – these include Ni, Ni-Co, Ni-Cr, nickel-based superalloys and complex steels.
(c) Friction materials for brake linings and clutch facings in which abrasive and other nonmetallicmaterials are embedded in either a copper or other metallic matrix.
(d) Diamond cutting tools, especially grinding wheels, including smallest particles of diamonds.(e) Processed dispersion-strengthened materials even resist high temperatures compared to various other materials.
(f) Composite magnetic materials made of iron powder particles – with no ability of these produced otherwise than by PM.