Comparative study of the microstructure and arc erosion resistance of Ag/Ti2AlX (X = C, N) electrical contact materials
Dandan Wang, Hongyu Zhu, MengYan Zheng, Qi Tang, Xu Jin, Wei Wei, Chengjie Lu, ZhengMing Sun
Abstract
A group of MAX phases including Ti 2 AlC and Ti 2 AlN, are candidate reinforcements of Ag-based electrical contact materials. In this work, the interfacial reaction, resistivity, hardness and arc erosion resistance of Ag/Ti 2 AlX (X = C, N) were investigated comparatively. During the sintering of both Ag/Ti 2 AlX, Al deintercalated from Ti 2 AlX and Ag diffused into Ti 2 AlX. The interfacial reaction was mild in Ag/Ti 2 AlN while obvious in Ag/Ti 2 AlC. The first-principles calculation indicated that the higher vacancy formation energy of Al in Ti 2 AlN led to the mild reaction in Ag/Ti 2 AlN, which then resulted in a larger decrease in hardness and resistivity, as compared with Ag/Ti 2 AlC. Moreover, Ag/Ti 2 AlN showed superior arc erosion resistance, with less evaporation of Ag and oxidation of Ti 2 AlC. This were attributed to the lower vulnerability of mildly decomposed Ti 2 AlN, less resistance heat and easier heat dissipation, resulting from the superior electrical and thermal conductivity .