Vacuum circuit interrupter contacts containing chromium dispersions

摘要

A powdered metallurgical procedure for forming chromium copper contacts used in vacuum circuit interrupters, in which prealloyed powder formed by mixing to copper, chromium of between two to thirty-seven weight percent is rapidly solidified after melting at about 1100 DEG C. to 1500 DEG C. This powder may be blended with additional chromium of between 12 to 50 weight percent with a maximum of fifty-five weight percent of chromium in the final contact structure. This blended mixture may then be either (i) cold pressed at 100,000 psig. and vacuum sintered at 800 DEG to 1400 DEG C.; or (ii) be subjected to hot isostatic pressure of 10,000 to 30,000 psig. at between 700 DEG C. to 1080 DEG C.; or (iii) containing the blended copper-chromium powder and the additional chromium powder into an evacuated can and hot extruding the can between 400 DEG C. to 900 DEG C., to form the contacts.