GB504803A - Improvements in or relating to the manufacture of articles from hard metal carbides - Google Patents

Abstract

504,803. Obtaining coherent masses from powdered metals; alloys. STEVENS, A. H. (Metal Carbides Corporation) Nov. 1, 1937, No. 29828. [Class 82 (i)] [Also in Groups V, III, XI, and XXII] Articles are formed from alloys of hard metal carbides with metals by heating the material within a mould to a predetermined temperature whereupon the heating is discontinued and pressure is applied. There may be a series of heating and pressing steps. The temperature may be 1500-2500‹ C. and the pressure 1 to 3 tons. The articles formed may be rolls, or roll-sheaths for metal-rolling presses, or bearings, or wire, rod, or pipe-drawing dies, or sandblast nozzles. The carbides may be tungsten, tantalum, titanium, vanadium or molybdenum and the metal may be iron, cobalt or nickel in a proportion of 1 to 60 per cent by weight. The mould may be formed by a graphite or carbon cylinder 1 supported on a base 2 and surrounded by powdered carbon 5 or other insulation and a quartz shield 3 within an electric induction heating coil 6. Plates 10, 14 are placed at the bottom and top of the material which is consolidated by a plunger 15 in a hydraulic or other press. For apertured or tubular articles such as dies, a core 13 is provided and the plates 10, 14 may be shaped as at 11 to produce throated apertures. The plate 14 may have vents 14a. The core may be coated with tantalum or titanium carbide to produce a hardened aperture. In forming rolls, pressure may be applied by a pair of opposed high-speed hydraulic presses 81, 82, Fig. 6, working through plungers 83, 84, bedplates 85, 86 and graphite plungers 87 with moulded endpieces 88. Axles of steel may be cast or welded on the ends of the roll.