Trimetal

(or trilayer), a metallic material in plate or sheet form that consists of three layers of unlike metals or alloys. An example of a trimetal would be a sheet of inexpensive carbon steel plated on both sides with expensive stainless steel. Trimetals are essentially similar to bimetals in both function and method of production. Three-ply semifinished products are also classified among the trimetals. They are used for welded and other joints in cases where direct contact between two metals is impossible—for example, between steel and titanium.