C107 Damage Evaluation of High Temperature Materials by EBSP Analysis

Fatigue and creep damage of Ni-base superalloys have been investigated using the electron back-scattering diffraction pattern (EBSP) method. The damage caused by high temperature fatigue test is detected as misorientation, and localize at the surface of damaged specimens. The value of misorientation tends to increase with increasing the fatigue damage. Creep damage is also evaluated as the misorientation, but localized around grain boundaries and interfaces of precipitates. The misorientation has a good correlation with the creep strain. Among some misorientation parameters applied in this study, orientation distribution (OD) shows better sensitivity and relativity to the damage than the other misorientation parameters.