CARBURIZED CARBIDE POWDER MIXTURE BASED ON TUNGSTEN AND CARBURIZED CARBIDE PRODUCT PRODUCED THEREFROM

摘要

PURPOSE: To obtain a sinterable powder mixture capable of forming an inexpensive and high-quality W-based carbide sintered body by specifying a composition comprising WC, an iron group metal binder, Ta (Nb) oxide, and powdered elemental C. CONSTITUTION: This powder mixture has a composition comprising, by weight, >=70% of WC, about 2-15% of iron group metal binder, about 1-8% of Ta (Nb) oxide, powdered elemental C, and optionally about <=15% of one or more kinds among the carbides, nitrides, and carbonitrides of the group IVb, Vb, and VIb metals of the periodic table. In this powder mixture, the above C powder is contained in about the stoichiometric amount required for the reaction: Ta(Nb)2 O5 +7C→2Ta(Nb)C+5CO. By sintering this powder mixture by a prescribed method, the W-based cemented carbide product excellent in hardness and fracture toughness can be obtained without forming cluster.