Patent ID: 6733874
Filing Date: 2004-05-11
Classification: C23C,Y10T

Abstract:
A surface-coated cemented carbide alloy cutting tool comprising a hard coating layer and a cemented carbide alloy substrate, the hard coating layer comprising:a Ti compound layer, as a lower layer, formed by vapor deposition, having, an average thickness of 0.5 to 20 &mgr;m, said Ti compound layer comprising at least one layer selected from the group consisting of a layer of a carbide of Ti, a layer of a nitride of Ti, a layer of a carbonitride of Ti, a layer of a carboxide of Ti, and a layer of a carbonitroxide of Ti; a first aluminum oxide layer, as an intermediate layer, having an average thickness of 1 to 25 &mgr;m, said first aluminum oxide layer having a heat transformed &agr;-type crystal structure derived from a vapor deposited &kgr;- or &thgr;-type aluminum oxide layer; and a second aluminum oxide layer, as an upper layer, formed by vapor deposition, having an average thickness of 0.3 to 10 &mgr;m, said second aluminum oxide layer having an &agr;-type crystal structure.