Influence and effectivity of Sm2O3 and Cr3C2 grain growth inhibitors on sintering of WCoB–TiC based cermets

Abstract With WC, TiB 2 and Co powders as raw materials, WCoB–TiC based cermets were prepared by liquid phase reaction sintering (LPRS) in a vacuum furnace at 1400 °C. In this work, the consolidation of WCoB–TiC based cermets with Sm 2 O 3 or Cr 3 C 2 as grain growth inhibitor was studied. The amounts of inhibitor are 0; 0.3; 0.6 and 0.9 wt%. The effects of Sm 2 O 3 and Cr 3 C 2 on the grain growth of WCoB–TiC based cermets were studied. The microstructure and mechanical properties of WCoB–TiC based cermets were analyzed by field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). It is found that that Sm 2 O 3 and Cr 3 C 2 not only retard the densification of the WCoB–TiC based cermets, but also significantly suppress the growth of WCoB-grains and TiC-particles. Specimens doped with 0.3 wt% Sm 2 O 3 exhibit the optimum mechanical properties (hardness and wear resistance). Whereas mechanical properties (hardness and wear resistance) of specimens linearly increase with the increase of Cr 3 C 2 .