Microstructure evolution of GH3600 alloy foil after long-term service in aero-engine
By using optical microscopy,scanning electron microscopy and energy spectrum analysis,the abnormal andnormal thermal insulation parts made of δ0.05 mm GH3600 foil with large oxidation difference after serving in the aero-engine for more than 400 hours were investigated. The results show that the grains in normal and abnormal parts after service are found to grow. Moreover,M7 C3 phase can still be observed in normal parts,but the amount is less thanthat of solution foil. However,M7 C3 phase in the abnormal part is almost completely dissolved. After service,the oxide layer of the foil with a two-layer structure in the abnormal part is thicker,and most of the grain boundaries have been oxidized and cracked. The surface oxidation layer of the normal parts is a single-layer structure and intergranular cracks exist only near the surface. The result shows that the abnormal parts are caused by the long-term overtemperature service.
万方数据
维普
