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 TaAlC is 15 mu m in length and 3 mu m 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 m(1/2), 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 degrees C, Ta2AlC still retains a high Young's modulus and shows excellent thermal shock resistance, which renders it a promising high-temperature structural material. (c) 2007 Elsevier Ltd. All rights reserved.