Abstract
This paper focused on microstructural changes in a single crystal Ni-base superalloy, CMSX-4, induced by external loadings. It was shown by a series of experiments that an application of the monotonic straining at R.T. and the subse-quent heat treatment at high temperature resulted in a directional coarsening of γ/γ' microstructure, similar to “rafted structure” by creep. A critical strain was found to be needed to build up the microstructural change. The coarsening direc-tions were significantly depending on the histories of straining. Not only monotonic but also cyclic loadings at R.T. and elevated temperatures could induce the similar changes in microstructure. These series of experimental works provide us a new method for failure and damage analysis of superalloy components.
