Diffusion of Boron in the Cemented Carbide (Part I)

Abstract

The authors have succeeded in obtaining a new and improved tool material which is harder than any existing cemented carbide by diffusing boron on the surface of the cemented carbide or cermet, the best tool material up to the present, by means of the electrolysis in the molten salts.
By using the test pieces of WC-Co alloy comprising cobalt of 4, 7 and 10% respectively, boron was diffused by means of electrolysis in the molten salts. We found that the surface hardness was increased by about 40 to 70%.
This increase in hardness is due to the boride produced by the combination of boron and cobalt. The diffused layer was 40μin thickness.
After a practical running test, it was found that the tool of this treated WC-Co alloy had the tool life three times as that of the tool without treatment and working efficiency was also increased.