Microstructure and properties of bulk Ta2AlC ceramic synthesized by an in situ reaction/hot pressing method

Dense bulk Ta2AlC ceramic was synthesized by an in situ reaction/hot pressing method using Ta, Al, and C as initial materials. The average grain size of Ta2AlC is 15 μm in length and 3 μm in width. The physical and mechanical properties were investigated. Ta2AlC is a good electrical and thermal conductor. The flexural strength and fracture toughness of Ta2AlC were measured to be 360 MPa and 7.7 MPa m1/2, respectively. The typical layered grains contribute to the damage tolerance of this ceramic. After indentation up to 200 N at the tensile surface of the beam specimens, no obvious decrease of the residual flexural strength was observed. Even at above 1200 °C, Ta2AlC still retains a high Young's modulus and shows excellent thermal shock resistance, which renders it a promising high-temperature structural material.