Abstract
Self-lubricative tungsten carbide bodies were prepared by electrical current activated sintering with the addition of carbon onion, and their mechanical and tribological properties were examined. The addition of carbon onion into the sintered tungsten carbide bodies led to reduced friction coefficients in both air and vacuum, in particular, at high temperature. On the other hand, Rockwell hardness and three-point bending strength declined. SEM observation of the fractured surface of the tungsten carbide bodies revealed that grain boundary fracture happened. Moreover, the aggregation of carbon onion and the pores were found on the fractured surface. These results would indicate that carbon onion works as a lubricant in the sintered bodies but not a binder between tungsten carbide particles.
