METHOD FOR PRODUCING COPPER-CHROME MELTING ALLOYS AS A CONTACT MATERIAL FOR VACUUM CIRCUIT BREAKER

摘要

A method of producing copper-chromium fusion alloys having a chromium content of at least 25% by mass and at most 60% by mass with a homogeneous macrostructure without lattice defects and without shrink holes or pipes, which can be used as contact material for vacuum power switches with breaking currents exceeding 10kA. According to the invention, during fusing of the starting material to the fusion alloy a superheating to at least 2000 DEG C. is obtained at least in a partial zone of the instantaneous melt volume. Thereafter the melt is cooled at a cooling rate such that no primary Cr precipitation or segregation occurs.