Abstract
In order to evaluate mechanical and thermal properties of WC-βt-Ti(C,N)-Co alloys consisting of four phases, the effects of additional Ti(C, N) content on mechanical and thermal properties of the alloys were mainly investigated. Moreover, cutting performance of the alloys in face milling was investigated comparing with the case of WC-βt-Co alloys with the same level of hardness. The results obtained were as follows; (1) The hardness increased with increasing Ti(C, N) content in the alloy. On the other hand, the fracture toughness and elastic modulus and thermal conductivity decreased with increasing Ti(C, N) content in the alloy. In other words, these changes of mechanical and thermal properties were considered to be mainly due to area proportion of WC phase in the microstructure of the alloy. However, the transverse-rupture strength scarcely changed by Ti(C, N) content in the alloy because the size of fracture origin consisting of the aggregated βt was almost same with no relation to Ti(C, N) content. (2) The cutting performance of WC-βt-Ti(C, N)-Co alloys was remarkably superior to that of WC-βt-Co alloys in wear resistance and surface roughness.
