How sintering process affects microstructure and properties of (Nb,V,Ta,Mo,W)C high‐entropy carbide

Abstract The hot‐pressing sintering technique was applied to prepare (Nb,V,Ta,Mo,W)C high‐entropy refractory metal carbides (HERC), and a series of processing were investigated to disclose the effect of sintering process on the microstructure and properties of the HERC. It was found that single‐phase HERC with a face‐centered cubic (FCC) structure can be obtained at 1600°C with a holding time of 10 min. However, it was not fully densified and the distribution of metal elements was not homogeneous. Further increasing the sintering temperature and extending the holding time resulted in obvious grain growth of HERC, thereby weakening the material performance. A two‐step sintering method was further developed, by which the relative density of HERC was increased, and a uniform solid solution with small grain size was obtained. The difference in grain growth characteristics of HERC in the high‐temperature range was elucidated quantitatively for both the two‐step sintering and the conventional sintering. The HERC prepared by the two‐step sintering exhibited excellent mechanical properties.