HIGH TEMPERATURE STABILITY OF MGC'S GAS TURBINE COMPONENTS IN COMBUSTION GAS FLOW ENVIRONMENTS

摘要

Melt growth composites (MGCs) have a unique microstructure, in which continuous networks of single-crystal phases interpenetrate without grain boundaries. Therefore, the MGCs have excellent high-temperature strength characteristics, creep resistance, oxidation resistance and thermal stability in an air atmosphere at very high temperature. In order to investigate the recession behavior of MGCs in combustion gas flow environment, we have just started the exposure tests to evaluate the influence of combustion gas flow environment on MGCs. The MGCs have about 95% of the initial flexural strengths after the exposure test for 10 hours at T = 1500°C, P = 0.1-0.3 MPa, V = 150-250 m/s, P_(H2O) = 15-45 kPa in the combustion gas flow environment. MGCs have excellent thermal stability and water vapor resistance in comparison with conventional ceramic materials such as Si_3N_4 and Al_2O_3 under the high temperature combustion gas flow environment.