JPH05311313

PURPOSE:To obtain a WC-base sintered hard alloy for mining tool for which crack propagation is inhibited by specifying the grain size distribution of WC and carbon content in a WC-base sintered hard alloy consisting of specific percentages of WC and binding phase composed essentially of Co. CONSTITUTION:In a WC-base sintered hard alloy used for the mining tool, etc., and consisting of, by weight, 80-95% WC and the balance binding phase, composed essentially of Co, with inevitable impurities, the grain size of hard phase is regulated, from the microstructure at the grinding surface, so that the hard phase consists of, by area ratio, 10-30% coarse-grain WC (>7mu), 30-60% medium-grain WC (4-7mu), and the balance fine-grain WC (