EXTRA-ABRASIVE GRAIN COATED WITH METAL CARBIDE, ITS MANUFACTURING METHOD AND EXTRA-ABRASIVE GRAIN TOOL

摘要

PROBLEM TO BE SOLVED: To provide extra-abrasive grain coated with metal carbide and its manufacturing method preventing the separation of metal carbide from the extra-abrasive grain and the degradation of the extra-abrasive grain due to the influence of heat when sintering to form an abrasive grain layer, and to provide an extra-abrasive grain tool having a long tool life.;SOLUTION: The extra-abrasive grains are held in a reaction chamber by heightening to a specified temperature, keeping the pressure reduced state of atmosphere, in the reaction chamber. Raw gas containing at least metal is then led in and held in the reaction chamber for a specified time, and the reaction chamber is exhausted so as to be in the pressure-reduced state. Steps of leading in the raw gas, holding and exhausting are repeated to coat the surface of the extra-abrasive grain with metal carbide. The extra-abrasive grain coated with metal carbide is provided with the extra-abrasive grain and a titanium carbide film formed to coat the surface of the extra-abrasive grain, and the average grain diameter of crystal grains of titanium carbide included in the titanium carbide film is 10 nm-30 nm.;COPYRIGHT: (C)2001,JPO