New binder phases for the consolidation of TiB2 hardmetals

New TiB2-based cermets have been consolidated by hot isostatic pressing of powder mixtures of TiB2 and metallic alloys based on Fe, Ni and Co additions. Relevant thermodynamic aspects of the systems B-Ti-Ni, B-Ti-Fe and B-Ti-Co, essential for avoiding the formation of extremely brittle secondary borides, especially the secondary boride M23B6, are discussed in this work. The role of contaminants like oxygen, carbon and nitrogen, which can also lead to the formation of these compounds is also explained. The hardness, toughness and cutting behaviour of the cermets produced with these new binder phases are comparable with the highest commercial WC-Co grades.