Microstructure and Compression Strength of W/HfC Composites Synthesized by Plasma Activated Sintering

In this work, W/HfC composite materials were synthesized using plasma activated sintering. The influence of the sintering temperature and HfC weight fraction on the relative density, microstructure and compression strength were investigated. The results demonstrated that the sintering temperature and the HfC content significantly affected the microstructure of W/HfC composites. Moreover, the grain size of the W/HC composites decreased and the mechanical properties were improved remarkably due to the addition of HfC. The majority of HfC particles reacted with oxygen impurities to generate HfO2, which purified the grain boundaries and refined the grain size of the W matrix. The optimum content of HfC is 2 wt%, at which a high compressive strength of 1.98 GPa and a high strain of 34.7% were obtained.