Sintered hard metal having superior toughness

摘要

A sintered hard metal having superior toughness and superior hardness may be used for micro-drills, tools and wear resistant parts. The metal is a cemented carbide WC formed from tungsten carbide WC as the base alloy and containing 4 to 20 percent by weight of vanadium carbide VC or zirconium nitride. Its micro-structure is that the WC or WC-VC particles are 0.6 mu or less, its Rockwell Hardness HRA is at least 91.5 and its transverse rupture strength is at least 350 kg/mm2.