Hot-pressing Sintering of Double-A-layer MAX Phase Mo2Ga2C

Abstract

Mo2Ga2C, a double-A-layer MAX, is reported to be films or powders. This paper researched the sintering properties of M2Ga2C powders to make dense bulk samples by vacuum hot pressing. It was found that 750 ℃ was a suitable sintering temperature, while higher temperature (850 ℃) resulted in decomposition of Mo2Ga2C yielding to main product of Mo2C. During sintering process at 750 ℃, its grain size did not increase obviously with sintering time, meanwhile the size of pores decreased markedly and the relative density increased significantly with the increasing sintering time. Additionally, the hot-pressed samples had obvious texture. Due to layering, some grains changed their orientations during sintering, of which most of the (00l) planes in the hot-pressed samples preferred to be perpendicular to the direction of hot press. Almost fully densed Mo2Ga2C bulk (relative density: 98.8%) was obtained by hot pressing at 750 ℃ for 8 h. This advantage of the method suggested that it can serve as a promising preparation for Mo2Ga2C, a double-A-Layer MAX.