Silver composite contacts prepared by means of fiber infiltration method and their properties

The commercial silver-Ni, or W, or CdO contacts have been produced mainly by the powder metallurgy, which seems to be rather expensive from a metallurgical viewpoint. In order to develope a more economical method, the infiltration method used to prepare fiber-reinforced metal composites was applied in the present work to make silver composite contacts with Ni continuous thin wire, alumina whisker SAFFIL, and carbon chopped fiber.Ag-Ni composite was successfully prepared by an unidirectional solidification, and Ag-alumina whisker and Ag-carbon fiber by a centrifugal infiltration method. The Ag-30wt%Ni (No.2) composite contact was found to have a superior contact property than the traditional Ag-15wt%Ni contact, and to be able to save a considerable amount of silver. The Ag-30vol% carbon composite contact showed a comparable property to Ag contacts, though its contact resistance was slightly larger.