Abstract

The effects of B_4C on the mechanical properties of WC/Ni-Si hardmetal were analyzed using sintered bodies comprising WC(70-x wt.%), Ni (28.5 wt.%), Si (1.5 wt.%), and B_4C (x wt.%), where 0leq_-xleq_-1.2 wt.%. Samples were prepared by a combination of mechanical milling and liquid-phase sintering. Phase and microstructure characterizations were conducted using X-ray diffractometry, scanning electron microscopy, and electron probe X-ray micro analysis. The mechanical properties of the sintered bodies were evaluated by measuring their hardness and transverse rupture strength. The addition of B_4C improved the sinterability of the hardmetals. With increasing B_4C content, their hardness increased, but their transverse rupture strength decreased. The changes of sinterability and mechanical properties were attributed to the alloying reaction between B_4C and the binder metal (Ni, Si).

• Keywords: Nickel base hardmetal;Boron carbide;Sintering;Mechanical property;