Optimization of the mechanical properties of ultra-fine WC-Co-Cr3C2 cemented carbides via an approach based on thermodynamic calculations and characterization of the experimental results by the Weibull distribution

The influence of sintering temperature on the grain distribution, mechanical properties and fracture probability of WC-10 wt% Co-Cr3C2 cemented carbide was studied. Based on thermodynamic calculations, the complete liquefaction temperature of the WC-10 wt% Co-Cr3C2 cemented carbides shows a descend trend with the increase of Cr content. The addition of 0.5 wt% Cr decreases the complete liquefaction temperature of the WC-10 wt% Co cemented carbides from about 1360 degrees C to 1310 degrees C, the sintering temperature were defined starting from this result and adding 30, 50 and 80 degrees C. For comparison, an industrial production sintering temperature of 1410 degrees C is also used. Compared with four sintering schedules, WC-10 wt%Co-0.5 wt% Cr cemented carbides has more uniform grain size and better mechanical properties at sintering temperature for 1360 degrees C. In addition, the fracture probability of WC-10 wt%Co-0.5 wt% Cr cemented carbides is improved at sintering temperature for 1360 degrees C. An appropriate sintering temperature can be established by thermodynamic calculations, which enables effectively control of grain size and mechanical properties.