Abstract
New TiC/Co 1.5 CrFeNi 1.5 Ti 0.5 cermet was developed by exploiting the advantages of the high-entropy alloy (HEA) binder. A much finer grain structure and thus improved hardness–toughness combination were obtained as compared with two traditional binders, Ni and Ni 13 Mo 7 . From the coarsening behavior of TiC grains, the coarsening process of TiC in these three binders is diffusion-controlled. The activation energy of TiC + 20%Co 1.5 CrFeNi 1.5 Ti 0.5 is the highest and that of TiC + 20%Ni is the lowest. The high activation energy of the Co 1.5 CrFeNi 1.5 Ti 0.5 binder was attributable to its high content of carbon-strong-binding elements, Cr and Ti, and cooperative diffusion and higher packing density of multiple different-sized atoms. Low diffusion coefficient, low surface energy of TiC grains, and low solubility of Ti in the HEA liquid explain the slow coarsening of TiC grains. This study demonstrates that Co 1.5 CrFeNi 1.5 Ti 0.5 is an excellent HEA binder for TiC cermets.