COATED CEMENTED CARBIDE BODY AND METHOD FOR CUTTING STEEL USING THE SAME

摘要

PROBLEM TO BE SOLVED: To improve a coated cemented carbide insert for cutting steel by allowing it to contain a cemented carbide substrate, Ti (C, N) intermediate layers of multilayers contg. a 1st inside layer of columnar particulate Ti (C, N) and a 2nd outside layer of equi-axed Ti (C, N), an Al2O3 layer and an another layer of columnar particulate Ti (C, N) on the Al2O3 layer. ;SOLUTION: The surface of a substrate is coated with a TiCN layer composed of columnar particles. The columnar particles have the width of 0.1 to 0.5 times the thickness of the coating layer and the length of 0.5 to 0.8 times the thickness of the coating layer. For improving the adhesion of a bonding layer, a TiCN layer composed of equi-axed particles is formed on the columnar TiCN layer. The particle size of the equi-axed particles is controlled to 0.2 to 1.0 μm. Then, the total thickness of the TiCN layers is controlled to 2 to 4 μm. The bonding layer is the one of cubic crystals of Ti (CO) contg. Al. A κAl2O3 layer on this layer has the thickness of 2 to 4 μm and is used as a thermal barrier layer. The κAl2O3 layer is protected by TiCN formed thereon.;COPYRIGHT: (C)2000,JPO