High Temperature Strength Characteristics of a Unidirectionally Solidified Al₂O₃/GdAlO₃ Eutectic Composite

Abstract

Authors have already reported eutectic ceramic composites such as Al2O3/Y3Al5O12 (YAG) or Al2O3/GdAlO3 (GAP) with neither colonies nor grain boundaries by using a unidirectional solidification method. The eutectic composites have a new microstructure, in which continuous networks of Al2O3 phases and oxide compounds (YAG, GAP) interpenetrate without grain boundaries, named as Melt Growth Composites (MGC). Therefore, the MGC materials have excellent high-temperature strength characteristics, superior oxidation resistance and thermal stability at 1,700 ^oC in the air atmosphere. Several useful applications of the MGCs can be recently considered, for example, gas turbines and power generation systems at very high temperatures. The high temperature strength characteristics and the thermal stability of Al2O3/GAP eutectic composite will be reported.