Physical and mechanical properties of bulk Ta4AlC3 ceramic prepared by an in situ reaction synthesis/hot-pressing method

Bulk Ta4AlC3 ceramic was prepared by an in situ reaction synthesis/hot-pressing method using Ta, Al, and C powders as the starting materials. The lattice parameter and a new set of X-ray diffraction data were obtained. The physical and mechanical properties of Ta4AlC3 ceramic were investigated. Ta4AlC3 is a good electrical and thermal conductor. The flexural strength and fracture toughness are 372 MPa and 7.7 MPa·m1/2, respectively. Typically, plate-like layered grains contribute to the damage tolerance of Ta4AlC3. After indentation up to a 200 N load, no obvious degradation of the residual flexural strength of Ta4AlC3 was observed, demonstrating the damage tolerance of this ceramic. Even at above 1200°C in air, Ta4AlC3 still retains a high strength and shows excellent thermal shock resistance, which renders it a promising high-temperature structural material.