CREEP OF CMSX-4 IN AN UNSTABLE ORIENTATION

摘要

Constant load creep testing was performed on single crystal nickel based superalloy CMSX-4 in the nominal orientation at 750℃ and 950℃ at a range of stress levels. Creep properties were observed to be highly anisotropic at 750℃, whereas the anisotropy was greatly reduced at 950℃. The underlying creep deformation mechanisms were investigated through optical microscopy, Electron Back Scattered Diffraction Patterns (EBSP) and specimen cross section shape changes. It is concluded that deformation at 750℃ is based on the {111}<112> type slip systems whereas at 950℃ it changes to the {111 }<101> type.