Abstract: 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.degree. C. to 1500.degree. 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.degree. to 1400.degree. C.; or (ii) be subjected to hot isostatic pressure of 10,000 to 30,000 psig. at between 700.degree. C. to 1080.degree. 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.degree. C. to 900.degree. C., to form the contacts.

Abstract: The present invention is directed to a process for preparing a body of polycrystalline silicon doped with aluminum comprising melting a mixture of silicon powder and aluminum powder, rapidly quenching the melt, grinding the solidified silicon-aluminum alloy and hot pressing to form a compact.

Abstract: A method of making electrical brushes from thousands of hair-like fibers comprises wetting the fibers to hold them together in a bundle, placing the bundle in a tube and reducing the opening in the tube to hold the fibers therein.

Abstract: A vacuum interrupter contact is formed of copper and chromium which exhibits high electrical conductivity and a high density of greater than about 95% of the theoretical density of the materials. The copper is the predominant constituent, and a mixture of copper and chromium powder is cold-pressed to form a compact which is then vacuum-sintered at a temperature below the melting point of the copper to achieve the desired high density.

Abstract: A powdered metallurgical procedure for forming chromium copper contacts used in vacuum interrupters, wherein by adding a small amount of copper powder to the difficult-to-press chromium powder, superior pressed properties are attained and a resulting chromium compact having higher green strength is produced. By practicing the teaching of this invention, vacuum interrupter contacts can be pressed to complex shapes. It is desirable to have a vacuum interrupter contact having an approximately 50% chromium composition. The low compacting pressure necessary to produce a 40% to 60% chromium powder concentrations yields a compact having a very low green strength which cannot be ejected from a die without falling apart; by adding a small amount of copper powder to the chromium powder before pressing a compact having a much higher green strength, which can be readily handled, is obtained. Using the disclosed process a press to shape contact having a variable density can be attained.