Patent ID: 6210726
Filing Date: 2001-04-03
Classification: C23C,Y10T

Abstract:
A cutting tool comprising:a body, said body at least partially made of a material selected from cemented carbide, cermet, ceramics, and high-speed steel, said body defining a substrate surface; anda coating applied to said substrate surface,said coating having a total thickness of 0.5 to 20 .mu.m,said coating comprising one or more layers containing a refractory compound,at least one of said layers having a thickness of 0.5 to 15 .mu.m,said one or more layers comprising a fine-grained crystalline .gamma.-Al.sub.2 O.sub.3 phase exhibiting significant X-ray diffraction reflexes from at least one of the (440) and (400) crystal planes, said at least one or more layers having a hardness of at least 20 GPa, a compressive stress of at least 1 Gpa, a grain size less than 0.1 .mu.m. and is essentially free of halogen impurities.