Facile Synthesis of High Entropy Carbide-based Cermets

Cemented carbides and cermets are WC and TiCN based composites in which hard phases are embedded inside Co-Ni binders. Since 100 years cemented carbides have been in use for several wear resistance applications e.g. cutting tools, drilling etc. However, due to the health, economic and supply risk concerns, in recent years serious efforts; both at industrial and academic level have been directed towards finding an alternative solution to substitute WC as hard phase and Co as binder phase. This PhD work focuses on the one-step synthesis of high entropy carbide-based cermets with a nickel binder. High entropy carbides (HEC) have emerged as a promising class of novel ceramics with superior hardness, elastic modulus, oxidation resistance and improved fracture toughness as compared to the mono, binary or ternary carbides, which makes them suitable hard phases for ceramic-metal composites. However, to create the high entropy effect, at least five or more different elements are required in equi- or near equi-molar concentrations. Therefore, it is important to develop strategies to synthesize these novel cermets in a cost-effective manner to suit the conventional cemented carbides and cermets processing route, and to understand their microstructure evolution, mechanical behaviour, and high temperature oxidation and wear resistance properties.