Cyclic deformation mechanisms of precipitation-hardened Inconel 718 superalloy

Cyclic deformation behavior of IN 718 fatigued at room temperature and 920 K was examined. A significant cyclic deformation softening was observed, and planar deformation bands were formed at both the temperatures. The coherent and ordered γ″ precipitates were observed to be sheared by dislocations moving on {1 1 1} slip planes. A model describing the formation of planar slip bands is given.