Properties of Carbide-Metal Cermets Prepared from Composite Powders by Direct Reduction and Carburization Process
The transition-metal carbide cemented by metal has excellent combined properties. In this study, cermets were prepared by vacuum sintering from carbide-metal composite powders. The transition- metal oxides (Cr2O3, MoO3, V2O5, Nb2O5 and TiO2), cementing-metal oxides (Co3O4 and NiO), and carbon black were used as raw materials to pre-synthesize composite powders such as Cr3C2-Co, Mo2C-Co, VC-Co, NbC-Co and TiC-Ni, by a direct reduction and carburization process in vacuum. Results show that the participation of Co3O4 and NiO as well as the vacuum circumstance were greatly propitious to the carburization of transition-metal oxides into carbides. The carbothermal condition was greatly improved by the direct reduction and carburization process.