Abstract: A cutting tool having a hard coating layer including: a Ti compound layer, as a lower layer, formed by vapor deposition, having an average thickness of 0.5 to 20 &mgr;m and made of at least one layer chosen from among a carbide of Ti layer, a nitride of Ti layer, a carbonitride of Ti layer, a carboxide of Ti layer and a carbonitroxide of Ti layer; an aluminum oxide layer, as an intermediate layer, which has an average thickness of 1 to 25 &mgr;m and a heat transformed &agr;-type crystal structure derived from a vapor deposited &kgr;- or &thgr;-type aluminum oxide layer, and having a structure having cracks therein formed during heat transformation uniformly dispersed; and an aluminum oxide layer, as an upper layer, formed by vapor deposition having an average thickness of 0.3 to 10 &mgr;m and an &agr;-type crystal structure.

Abstract: A cutting tool having a hard coating layer including: a Ti compound layer, as a lower layer, formed by vapor deposition, having an average thickness of 0.5 to 20 &mgr;m and made of at least one layer chosen from among a carbide of Ti layer, a nitride of Ti layer, a carbonitride of Ti layer, a carboxide of Ti layer and a carbonitroxide of Ti layer; an aluminum oxide layer, as an intermediate layer, which has an average thickness of 1 to 25 &mgr;m and a heat transformed &agr;-type crystal structure derived from a vapor deposited &kgr;- or &thgr;-type aluminum oxide layer, and having a structure having cracks therein formed during heat transformation uniformly dispersed; and an aluminum oxide layer, as an upper layer, formed by vapor deposition having an average thickness of 0.3 to 10 &mgr;m and an &agr;-type crystal structure.

Abstract: A cutting tool having a hard coating layer including: a Ti compound layer, as a lower layer, formed by vapor deposition, having an average thickness of 0.5 to 20 &mgr;m and made of at least one layer chosen from among a carbide of Ti layer, a nitride of Ti layer, a carbonitride of Ti layer, a carboxide of Ti layer and a carbonitroxide of Ti layer; an aluminum oxide layer, as an intermediate layer, which has an average thickness of 1 to 25 &mgr;m and a heat transformed &agr;-type crystal structure derived from a vapor deposited &kgr;- or &thgr;-type aluminum oxide layer, and having a structure having cracks therein formed during heat transformation uniformly dispersed; and an aluminum oxide layer, as an upper layer, formed by vapor deposition having an average thickness of 0.3 to 10 &mgr;m and an &agr;-type crystal structure.

Abstract: The present invention relates to a coated cemented carbide cutting tool member, which includes: a substrate and a hard coating layer deposited on the substrate, wherein the hard coating layer has an average thickness of 3 to 25 &mgr;m and includes: (1) at least one layer having an average thickness of 0.1 to 5 &mgr;m and including a granular Ti compound selected from the group including TiC, TiN, TiCN, Ti2O3, TiCO, TiNO, TiCNO and mixtures thereof; (2) a TiCN layer having an average thickness is 2 to 15 &mgr;m and including a longitudinal growth crystal structure; and (3) an Al2O3 layer having an average thickness of 0.5 to 8 &mgr;m; wherein the TiCN layer includes a growth direction and a compositional gradient of carbon and nitrogen along the growth direction.

Abstract: A cutting tool having a hard coating layer including: a Ti compound layer, as a lower layer, formed by vapor deposition, having an average thickness of 0.5 to 20 &mgr;m and made of at least one layer chosen from among a carbide of Ti layer, a nitride of Ti layer, a carbonitride of Ti layer, a carboxide of Ti layer and a carbonitroxide of Ti layer; an aluminum oxide layer, as an intermediate layer, which has an average thickness of 1 to 25 &mgr;m and a heat transformed &agr;-type crystal structure derived from a vapor deposited &kgr;- or &thgr;-type aluminum oxide layer, and having a structure having cracks therein formed during heat transformation uniformly dispersed; and an aluminum oxide layer, as an upper layer, formed by vapor deposition having an average thickness of 0.3 to 10 &mgr;m and an &agr;-type crystal structure.

Abstract: A coated cemented carbide cutting member for a cutting tool comprising a substrate and a hard coating layer on said substrate, wherein the hard coating layer comprises at least one layer selected from the group consisting of titanium carbide, titanium nitride, titanium cabonitride, titanium carboxide, titanium carbonitroxide, aluminum oxide, and aluminum oxide-zirconium oxide composite in which zirconium oxide phases are dispersed around ground aluminum oxide phases, and wherein the hard coating layer is provided with an outer layer which comprises titanium oxide which is expressed by the molecular formula TiOw, wherein w is the atomic ratio of oxygen to titanium which ranges from 1.20 to 1.90.

Abstract: The present invention relates to a coated cemented carbide cutting tool member, which includes:

Abstract: The present invention relates to a coated cemented carbide cutting tool member, which includes: a substrate and a hard coating layer deposited on the substrate, wherein the hard coating layer has an average thickness of 3 to 25 &mgr;m and includes: (1) at least one layer having an average thickness of 0.1 to 5 &mgr;m and including a granular Ti compound selected from the group including TiC, TiN, TiCN, Ti2O3, TiCO, TiNO, TiCNO and mixtures thereof; (2) a TiCN layer having an average thickness is 2 to 15 &mgr;m and including a longitudinal growth crystal structure; and (3) an Al2O2 layer having an average thickness of 0.5 to 8 &mgr;m; wherein the TiCN layer includes a growth direction and a compositional gradient of carbon and nitrogen along the growth direction.

Abstract: The present invention provide for a cutting tool member that has been coated with a hard coating. The hard coating has multiple layers including: a) a layer made of a titanium compound that has a cubic lattice structure, b) an Al.sub.2 O.sub.3 layer, and c) an intervening layer that includes a Ti.sub.2 O.sub.3 compound with a corundum-type lattice structure. The hard coating layer provides the cutting tool member with good strength and increases its operational lifetime.