CUTTING TOOL WITH MULTILAYER COATING Russian patent published in 2003 - IPC

FIELD: tool manufacture, namely application of wear resistant coatings onto cutting tools. SUBSTANCE: cutting tool includes tool base of quick-cutting steel and multilayer wear resistant coating applied onto base by ion- plasma method. Main outer coating contains nitride (of titanium, zirconium) at next relation of ingredients (mass %): titanium, 88 -92; zirconium, 8 - 12. Inner adhesion underlayer contains nitride (of titanium, zirconium, ferrum, nickel, chrome) with thickness 2 - 3 micrometers at next relation of metals in nitride (mass %): titanium, 86.5 - 91.0; zirconium, 8.0 - 12.0; ferrum, 0.7 - 1.04; nickel, 0.13 - 0.2; chrome, 0.17 - 0.26. There is additional underlayer of titanium, zirconium, ferrum, nickel and chrome between tool base and adhesion underlayer; said additional underlayer has thickness 1.5 micrometers at next relation of ingredients (mass%): titanium, 86.5 - 91.0; zirconium, 8.0 - 12.0; ferrum, 0.7 - 1.04; nickel, 0.13 - 0.2; chrome, 0.17 - 0.26. Total thickness of coating consists 6.5 micrometers. EFFECT: lowered residual stresses, enhanced cohesion of coating and tool base, improved strength of cutting tool. 1 dwg, 1 tbl