Melt growth composites (MGCs) have a microstructure, in which continuous networks of single-crystal Al2O3 phases and single-crystal oxide compounds (YAG (Y3Al5O12), GAP (GdAlO3)) interpenetrate without grain boundaries. Therefore, the MGCs have excellent high-temperature strength characteristics, creep resistance, superior oxidation resistance and thermal stability in the air atmosphere at very ... [Show full abstract] high temperature. To achieve ultra-high thermal efficiency and low NOx emission for gas turbine systems, we produced turbine nozzle vanes that does not require cooling and heat shield panels for combustor liners. The thermal stability and mechanical properties of these parts have been studied. The high-temperature strength characteristics and the thermal stability of components were also no changes after heat treatment for 500 h at 1700 °C in an air atmosphere. The favorable properties of melt growth composite have been discussed for possible application in gas turbine system.