Method of fabricating a contact material for high-power vacuum circuit breakers

摘要

A method of fabricating a contact material for high-power vacuum circuit breakers. In the method, an alloy consisting essentially of a base metal having a melting point above about 1000° C and below about 1800° C, at least one alloying metal which will not form a solid solution with the base metal, and at least one auxiliary metal which forms a eutectic with the base metal are melted under vacuum at a temperature between about 1000° C and about 1800° C. The molten alloy is then slowly cooled so as to form fine grain crystals of the base metal and auxiliary metal in solid solution in the eutectic while the eutectic is a liquid and transfer gases expelled from the crystals during the cooling to the liquid eutectic to increase the concentration of gases in the liquid eutectic above an equilibrium concentration, cause evacuation of the gases from the liquid eutectic, and remove the gases from the alloy. The alloy is then cooled to rapidly solidify the liquid eutectic and precipitate the alloying metal as a fine dispersion in the eutectic.