Orientation dependence of fracture toughness and fatigue crack growth resistance for in-situ A1_{2O_{3/YAG eutectic composites

MGC materials, which are in-situ single crystal oxide ceramics eutectic composites have many potentialities, such as high-strength, high creep resistance, and high oxidation resistance at ultrahigh temperature. In the New Sunshine Program of Agency of Industrial Science and Technology, a leading research and development has started since FY1998 for three years to apply MGC materials on ultrahigh temperature structural materials for gas turbine system. In this paper, the current activities of the Mechanical Engineering Laboratory in the leading research and development is shown. The influences of solidification direction on fracture toughness and fatigue crack growth resistance for A12O3/YAG eutectic composites are discussed.