Abstract

A cemented tungsten carbide body is formed by mixing a tungsten carbide powder and a cobalt powder together to form a powder mixture. The tungsten carbide powder makes up greater than or equal to 80 weight percent of the powder mixture, while the cobalt binder powder makes up about 1.5 weight percent to about 20 weight percent of the powder mixture. Next, the powder mixture is compacted to form a green compact, and a boron nitride coating is applied to a surface of the green compact to form a coated compact. The coated compact is sintered at a temperature sufficient to melt the cobalt powder, such that boron from the boron nitride coating diffuses into the compact and creates a gradient of metallic cobalt and boron extending inward from the surface. The metallic cobalt content increases from the surface inward, while the boron content decreases from the surface inward.

IPC Classes  ?

• C22C 29/08 - Alloys based on carbides, oxides, borides, nitrides or silicides, e.g. cermets, or other metal compounds, e. g. oxynitrides, sulfides based on carbides or carbonitrides based on carbides, but not containing other metal compounds based on tungsten carbide