Effects of microstructure and lattice misfit on creep life of Ni-based single crystal superalloy during long-term thermal exposure

作者：Gan, Wenyan^*; Gao, Hangshan; Pei, Haiqing; Wen, Zhixun

来源：International Journal of Materials Research, 2021, 112(3): 203-214.

DOI：10.1515/ijmr-2020-7774

• Single crystal superalloy
• Thermal exposure
• Microstructure evolution
• Creep life

According to the microstructural evolution during long-term thermal exposure at 1 100 degrees C, the creep rupture life of Ni-based single crystal superalloys at 980 degrees C/270 MPa was evaluated. The microstructure was characterized by means of scanning electron microscopy, X-ray diffraction and related image processing methods. The size of gamma' precipitates and the precipitation amount of topologically close-packed increased with the increase in thermal exposure time, and coarsening of the gamma' precipitates led to the simultaneous increase of the matrix channel width. The relationship between the creep rupture life and the lattice misfit of gamma/gamma', the coarsening of gamma' precipitate and the precipitation of TCP phase are systematically discussed. In addition, according to the correlation between gamma' phase evolution and creep characteristics during thermal exposure, a physical model is established to predict the remaining creep life.

• 单位
  西北工业大学; 常州工学院