DIAMOND SINTERED COMPACT TOOL EXCELLENT IN RESISTANCE TO DEPOSITION, AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To obtain a tool excellent in resistance to deposition at the working of a soft metal, particularly of an Al alloy, by forming a surface layer containing at least one kind selected among Si, Si oxides, Si carbides, Si nitrides, and solid solutions of them on the surface of the tool cutting face or tool flank of a tool stock. SOLUTION: SiO2, SiC and Si3N4 are preferred as Si oxide, Si carbide, and Si nitride, respectively. The thickness of the surface layer is preferably 1Åto 1μm. Moreover, it is preferable that the diamond sintered compact has an inner part containing ferrous metal in a first content and an outer part surrounding the inner part and containing ferrous metal in a second content lower than the first content and, further, the second content is 2.0 wt.% or below and the thickness of the part having the second content is 2 to 5,000 nm from the surface of the diamond sintered compact. As to the formation of the surface layer, Si powder is pressed against the surface to form an Si adsorption layer in the case of Si, while plasma CVD is adopted in the case of Si oxide, etc.