Patent ID: 7083868

Claim:
A cutting tool insert comprising a substrate and a coating wherein the coating comprising one or more layers of refractory compounds of which at least one layer comprises a composite structured (Ti y Al x Me 1−x−y )N layer, where Me is one of the elements Zr, Hf, V, Nb, Ta, Cr, Mo, W or Si, and wherein: x is between 0.60 and 0.80; a ratio, R=x/(x+y), is between 0.60 and 0.85; a sum of Ti and Al subscripts, S=x+y, is between 0.7 and less than 1.0; co-existence of crystalline hexagonal h-AlN and cubic c-(Ti y Al x Me 1−x−y )N as detected by X-ray diffraction (XRD), defined by the ratio K between the area of the h-AlN (100) peak at approximately 33° 2θ (=A(h-AlN) 100 ) and the c-(Ti y Al x Me 1−x−y )N (200) peak at approximately 43° 2θ (=(c-(Ti,Al,Me)N) 200 ) wherein K=A(h-AlN) 100 /A(c-(Ti,Al,Me)N) 200 , and K is >0.08; and a Full Width Half Maximum value of the c-(Ti b Al a Me 1−a−b )N (200) peak <1.4° 2θ, and the value of the h-AlN (100) peak is between 0.2 and 1.5° 2θ.