Study on the high temperature microstructure stability of the high Al content Ni-based single crystal superalloy

Abstract The high-temperature structure stability of high Al content Ni-based single crystal superalloy was studied, the microstructure was observed, and the micro-mechanism of the thermal stability of the material was analyzed. The results show that the exposure time and exposure temperature have significant effects on the stability of the alloy’s high-temperature structure. With the increase of exposure temperature and/or exposure time, the γ’ phase in the material becomes coarser, gradually connects and grows, and the stability of the material structure is obviously reduced. Compared with standard heat-treated alloys after high temperature exposure, The absolute value of the γ’ and γ phases misfit increases significantly. With the increase of exposure time, although the absolute value of the two-phase misfit continues to increase, the increase of its absolute value gradually slows down. The long-term structural stability of the alloy under continuous exposure to high temperature environment is good.