Patent ID: 8003232

Claim:
A cutting tool insert, comprising: a substrate selected from the group consisting of cemented carbide, cermet, ceramics, cubic boron nitride based material, and high speed steel; and a hard and wear-resistant coating comprising laminar polycrystalline metal nitrides layers; wherein said laminar polycrystalline metal nitrides layers have a repetitive form . . . A/B/A/C/A/B/A/C/ . . . with a total thickness of about 0.5 μm to about 5 μm; wherein layer A is a cubic structured MeN, and Me is one or more of the metal elements selected from the group consisting of Ti, Nb, Hf, V, Ta, Zr, Cr, and Al; wherein layer B is a cubic structured (Ti,Al)N; and wherein layer C is a cubic structured (Ti,Si)N; wherein the average composition of said laminar polycrystalline metal nitride layers is about 46 atomic share (at-%)<Zr+Hf+V+Cr+Nb+Ta+Ti+Al+Si<about 54 at-% and balance N; wherein an average thickness of each of said layer A (d A ) is about 2 nm<d A <about 100 nm; wherein an average thickness of each of said layer B (d B ) is about 4 nm<d B <about 150 nm; and wherein an average thickness of each of said layer C (d C ) is about 4 nm<d C <about 150 nm; and wherein said average thickness of each of said layer A, said layer B, and layer C is substantially constant throughout said coating.