Patent ID: 6612787
Filing Date: 2003-09-02
Classification: B22F,C22C,C23C,Y10T

Abstract:
A coated cutting insert comprising:a tungsten carbide-based substrate having a rake surface and a flank surface, the rake surface and the flank surface intersect to form a substrate cutting edge; the substrate comprising tungsten and carbon and between about 5.7 weight percent and about 6.4 weight percent cobalt, between about 0.2 weight percent and about 0.8 weight percent chromium, and having a coercive force (Hc) of about 195 to 245 oersteds; and a coating on the substrate wherein the coating includes a layer of alumina applied by chemical vapor deposition; wherein the coating includes a base coating layer containing chromium wherein the chromium diffuses from the substrate during the coating process.