The effects of Mo2C additions on the sintering response of TiC0.3N0.7–Ni3Al cermets

Abstract

This work explores the incorporation of Mo2C additions into TiC0.3N0.7–Ni3Al cermets from a thermal analysis perspective. The individual powder components were first characterised through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). It was observed that increasing concentrations of Mo2C decreased the onset temperature of both melting and solidification of the Ni3Al. Higher concentrations of Mo2C showed this decrease to be the result of peak convolution and that a secondary peak developed in both the melting and solidification peaks. This second peak is likely associated with the formation of a Mo-rich alloy phase, present in all microstructures containing both TiC0.3N0.7 and Mo2C. Additionally, weight loss observed in pure Mo2C powder, and attributed to the sublimation of MoO3, is not observed in the cermets prepared within this paper. It is thus suggested that Mo is incorporated into the Ni3Al through the reduction of MoO3, which explains the enhanced dissolution of Mo2C observed in previous studies.