PURPOSE: To manufacture a W-Ni-Fe sintered alloy having high strength and high ductility by mixing the powder of W, Ni and Fe in a specified ratio, forming it, executing specified sintering in a short time, thereafter rapidly cooling it at a specified cooling rate. ;CONSTITUTION: Metallic powdery materials contg., by weight, 85 to 98% W, and the balance essentialy Ni and Fe are mixed, and compacted. As for the metallic powder to be used, the particle diameter of W powder is preferably regulated to about 1 to 3μm, that of Ni powder to about 1 to 3μm and that of Fe powder to about 1 to 3μm. Then the green compact is held to a heating temp. of 1460 to 1560°C for ≤50min and is sintered. As this time as necessary, preliminary sintering is executed at 1300 to 1400°C for about 1 to 4hr in an evacuated reducing atmosphere such as gaseous H2 of ≤40Torr before the sintering. Moreover, preferably, the sintering is executed in a continuous annealing furnace to attain high efficiency. The sintered alloy is cooled at ≥5°C cooling rate to prevent the coarsening of the W grains and the precipitation of Ni and Fe.;COPYRIGHT: (C)1993,JPO&Japio
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