Method of producing shaped metal bodies by the hot pressing of metal powders

摘要

700,658. Powder metallurgy. METRO-CUTANIT, Ltd. Dec. 20, 1951 [June 26, 1951], No. 29901/51. Class 83 (4) In a method of producing metal bodies by hot pressing metal powders at between 100‹ and 800‹ C., a protective atmosphere is obtained by mixing the metal powders with substances which give off neutral or reducing gases at or below the pressing temperature and then applying the pressure immediately after all the gas has been given off. The substances to be mixed with the metal powders may leave a solid residue, for example, hydrides, or may be completely transformed into gas or vapour, for example, ammonium carbonate, methyl alcohol and other volatile organic reducing agents. Copper powder mixed with methyl alcohol is loaded into a die heated to 400‹ C. and after the complete evolution of the vapour, in 10 to 20 seconds, is pressed at 5 tons per square cm. In another example, to a mixture of silver and nickel powders is added 4 per cent of ammonium carbonate and the mixture loaded into a die heated to 350‹ C.