CUTTING TOOL OF SURFACE-COATED CERMET WITH THICK FILM alpha-TYPE ALUMINUM OXIDE LAYER ACHIEVING EXCELLENT CHIPPING RESISTANCE

摘要

PROBLEM TO BE SOLVED: To provide a cutting tool of surface-coated cermet comprising thick filmα-type aluminum oxide layer achieving excellent chipping resistance. SOLUTION: A hard coating layer formed by deposition on the surface of a tool base of this cutting tool of surface-coated cermet is composed of (a) a lower layer comprising a tight adhesion Ti compound layer comprising at least one layer of a TiC layer, a TiN layer, a TiCN layer, a TiCO layer, and a TiCNO layer, having total average thickness of 0.1-5μm, and a modified TiCN layer having average layer thickness of 2.5-15μm, and (b) an upper layer comprising a thick modifiedα-type Al2O3layer having average layer thickness of 16-30μm, andα-type crystal structure in a chemically deposited state. The modified TiCN layer in (a) and the thick modifiedα-type Al2O3layer in (b) respectively indicate specific component atom shared lattice point distribution graphs. COPYRIGHT: (C)2007,JPO&INPIT