SINTERED BODY OF WC-CO ALLOYS HAVING HIGH TOUGHNESS AND HEAT RESISTANCE

摘要

The present invention relates to a chipping resistance, chipping resistance and temperature of cemented carbide with increased wear resistance the sintered and coated cemented carbide cutting tool by the sintered body as the base material during the cutting process to control and high toughness, and the microstructure of the sintered body to have a heat resistance .; According to the invention, of 68 ~ 88% WC and contains Co binding phase of 5 to 12% and the Periodic Table 4a, 5a, and one or more kinds of additives selected from the group consisting of carbide, nitride and carbonitride of 6a Group element 7-20 % is provided with a cemented carbide sintered body comprising, combining a frequency larger than the 1.5㎛ combined phase structure in the microstructure is a predetermined range of the cemented carbide is less than 10 and is less than the magnitude of the maximum binding phase structure 2.5㎛, by controlling so as to have a binding phase in pure Co content is not less than 65% by weight characterized thereby increasing the heat resistance and the high temperature wear resistance of the tool. In addition, it is possible to improve the chipping resistance and chipping resistance by controlling the microstructure in the diameter than the WC 3㎛ area ratio is at least 80% of the total area ratio of WC. So the produced cemented carbide sintered body as the base material and made of a thin film composed of a material having a higher hardness than the base material coated cemented carbide cutting tool exhibits excellent cutting performance in the lesson intermittent and continuous cutting process.