Improvements in or relating to the manufacture of sintered metal articles

Abstract

Abstract Sintered metal articles containing voids, ducts or holes are produced by compacting metal powder about formers composed of a core of a metal e.g. Cd volatilisable at a temperature lower than the sintering temperature, coated with at least one metal which is a constituent of the metal powder and which dissolves in or combines with the core metal, heating the compact to volatilise the core metal and finally sintering the compact. In an example powders to form a nickel based alloy containing 20% Cr, 16% Co, 2,35% Ti, 1,35% Al, 0,07%-0,1%C. and 0,05%B are packed in layers in a floating die with formers consisting of cadmium wire 0,05 inches diameter coated with a layer of nickel 0,004 inches thick. Each powder layer is prepressed at 1 1/2 tons per square inch and the whole assembly is compacted at 35 tons per square inch. The ends of the compact are machined to expose the ends of the formers and the cadmium is then volatilised by heating the compact at 650 DEG C. in vacuum. Final sintering is carried out at 1300 DEG C. to 1325 DEG C. in vacuum or in a hydrogen atmosphere. Specification 611,466 is referred to.ALSO:Sintered metal articles containing voids, ducts or holes are produced by compacting metal powder about formers composed of a core of a metal e.g. Cd volatilisable at a temperature lower than the sintering temperature coated with at least one metal which is a constituent of the metal powder and which dissolves in or combines with the core metal, heating the compact to volatilise the core metal and finally sintering the compact. In an example powders to form a nickel based alloy are packed in layers in a floating die with formers consisting of cadium wire 0,05 inches diameter coated with a layer of nickel 0,004 inches thick. Each powder layer is prepressed at 1 1/2 tons per square inch and the whole assembly is compacted at 35 tons per square inch. The ends of the compact are machined to expose the ends of the formers and the cadmium is then volatilised by heating the compact at 650 DEG C. in vacuum. Specification 611,466 is referred to.

Inventors

• 👤 Horace James Coomber

Bibliographic Details