Surface hardening of tungsten-based heavy alloy via pack boronizing

The boronizing of a tungsten heavy alloy containing ni and fe as the major alloying elements were performed in the present study to increase its surface hardening. pack cementation method was employed as a well-known,successful solid-state process for boronizing. the coating treatment was accomplished at different temperatures of 1000,1050 and 1100°c for 6 and 9 hours. the formation of tungsten boride phase was confirmed,although a silicide layer covered the surface of the specimen as the outer layer. the mechanism of the formation of a multilayered surface was explained. the maximum thickness of reaction zone and surface hardness achieved in the current work were 300 µm and 2470 hv,respectively. © 2017,iran university of science and technology. all rights reserved.