CEMENTED CARBIDE ALLOY FOR CUTTING TOOL AND COATED CEMENTED CARBIDE ALLOY.

摘要

A coated cemented carbide alloy composed of the base material comprising a WC-base cemented carbide alloy containing 4-10 wt.% of cobalt as the binder phase and the coating layer with the overall thickness of 5-100 mu m formed on the surface of the alloy. The alloy as the base material has a cross section, after being mirror-finished, wherein at least 70 % of the WC crystals as the hard phase comprise either fine particles A with a diameter of 0.1-1 mu m or fine particles B with a diameter of 3-10 mu m and the areal ratio (SA/SB) of the particles A and B ranges from 0.22 to 0.45. The coating layer is composed of at least one layer containing at least a carbide, nitride, carbonitride, carbonate or boronitride of titanium, zirconium and/or hafnium and at least one layer containing at least an oxide of titanium, zirconium or hafnium or Al2O3.