| 摘要 |
PURPOSE:To provide a coated sintered hard alloy for thick Al2O3 film coated tools having good performance for high-speed cutting in the coated sintered hard alloy consisting of an outside layer of Al2O3 and an inside layer of TiC, TiN, etc., by laminating the outside layer by a chemical vapor deposition method then repeating said method and a plasma chemical vapor deposition method. CONSTITUTION:An inside layer of >=1 kinds among TiC, TiN, TiCN, SiC, Si3N4 is coated on a base material for a sintered hard alloy. Crystallized Al2O3 of fine particles up to 2mu is coated on the surface thereof as an outside layer by a chemical vapor deposition method, and further a plasma chemical vapor deposition method and the chemical vapor deposition method are repeated on the surface thereof. The coated layer having the laminated structure of amorphous Al2O3 or a mixed layer of the same and crystallized Al2O3 and the layer of only the Al2O3 is thus obtd. The Al2O3 film nearest the inside layer has high adhesion strength and the rate of growth for Al2O3 to be effected in succession is high; therefore, the film thickness is increased and said film has excellent adhesion to the Al2O3 nearest the inside layer, according to the above-mentioned method. |
