材料期刊网

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 degrees C. By modifying the molar ratio of the initial Ta, Al, and C powders, single-phase Ta(2)AlC was prepared at 1550 degrees 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 degrees C and decomposed to Ta(4)AlC(3), and then to TaC(x).