Chunfeng Hu, Jie Zhang, Yiwang Bao, Jingyang Wang, Meishuan Li, Yanchun Zhou
June 11, 2013
Dense bulk Ta 2 AlC ceramic was fabricated by in-situ reaction/hot pressing of Ta, Al and C powders. The reaction path and effects of initial composition on the purity were investigated. It was found that Ta 2 AlC formed through the reactions between AlTa 2 and graphite, or between Ta 5 Al 3 C, TaC and graphite at 1500–1550°C. By modifying the molar ratio of the initial Ta, Al, and C powders, single-phase Ta 2 AlC was prepared at 1550°C under an Ar atmosphere with an optimized composition of Ta: Al: C = 2: 1.2: 0.9. The lattice parameter and a new set of X-ray diffraction data of Ta 2 AlC were obtained. In addition, Ta 2 AlC was reported unstable above 1600°C and decomposed to Ta 4 AlC 3 , and then to TaC x .