PURPOSE: To obtain a coated sintered hard alloy having improved toughness and wear resistance and suitable for use as the material of a cutting tool, etc. by coating a sintered hard alloy as a base material with at least 1 layer of amorphous alumina.
CONSTITUTION: The surface of a sintered hard alloy is coated with an amorphous alumina layer in about 0.5W10μm thickness by a physical vapor deposition method (PVD) such as ion sputtering or a chemical vapor deposition method (CVD). The alloy surface may be coated with an amorphous alumina layer as the outermost layer with a TiC layer in-between so as to adjust the total thickness of the layers to about 0.5W20μm. By the coating with amorphous alumina a coated sintered hard alloy superior to a conventional sintered alloy coated with alumina in toughness and wear resistance is obtd.
DOI AKIRA
SHIMIZU YASUHIRO
