Fabrication of WC-TiC Based Hard Material by MA-PCS Process

Abstract

WC-23%TiC-6%Ni-8%Co powder was prepared by a mechanical alloying for a short time. When the MA powder was consolidated by a pulsed current sintering process, the hard composite material with the hardness of 92.1 HRA and the transverse rapture strength of 1455 MPa was obtained. When Ti powder and graphite powder were used for mechanical alloying as starting materials instead of TiC powder, TiC particles were synthesized during the pulsed current sintering. Although the obtained sintered body had fine structure, the transverse rapture strength of it was lower than that of the case with TiC powder used. It would be attributable to the remaining pores and the unstable metallic binder phases in the sintered WC-23%TiC-6%Ni-8%Co body. The new process of the mechanical alloying for a short time combined with the pulsed current sintering was effective to obtain a hard composite material with higher strength than that of ordinary vacuum sintering process because of its fine microstructure.