J. Mater. Sci. Technol. ›› 2019, Vol. 35 ›› Issue (9): 1917-1924.DOI: 10.1016/j.jmst.2019.05.026

• Orginal Article • Previous Articles     Next Articles

Influences of Re on low-cycle fatigue behaviors of single crystal superalloys at intermediate temperature

Liu Liuab, Jie Menga*(), Jinlai Liua, Mingke Zoua, Haifeng Zhangc, Xudong Sunb, Yizhou Zhoua   

  1. a Superalloys Division, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China
    b Key Laboratory for Anisotropy and Texture of Materials, Northeastern University, Shenyang, 110819, China
    c Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China
  • Received:2019-03-01 Revised:2019-04-01 Accepted:2019-04-30 Online:2019-09-20 Published:2019-07-26
  • Contact: Meng Jie
  • About author:

    1 These authors contributed equally to this work.

Abstract:

Low-cycle fatigue behaviors of Ni-base single crystal superalloys containing different Re contents have been investigated at 760 °C. During heat treatment, Re retards γ′ phases coarsening and equalizes the distribution of γ′ phases. As Re content increases, fatigue life increases and slip bands distribute more inhomogeneously. Moreover, adding Re not only reduces stacking fault energy of the matrix, but also promotes the element segregation to increase the lattice misfit. However, the larger lattice misfit does not lead to the formation of dislocation networks, but which activates dislocation movement and promotes dislocations cross-slip and climbing movement under high temperature and applied stress. On the other hand, with the addition of Re, cyclic deformation behaviors change from cyclic hardening to cyclic stability, mainly depending on a transformation of deformation mechanisms from slip bands cutting through γ and γ′ phases to stacking faults shearing.

Key words: Single crystal superalloys, Low-cycle fatigue, Deformation behaviors, Deformation mechanisms