Interaction processes between dislocations and particles in the ODS nickel-base superalloy INCONEL MA 754 studied by means of in situ straining in an HVEM

In situ straining experiments in a high-voltage electron microscope (HVEM) have been performed on the oxide-dispersion strengthened (ODS) nickel-base superalloy INCONEL MA 754 at 1020 and 1065 K. The results can be interpreted by interfacial pinning of dislocations at the dispersoids and, in some cases, by the Orowan mechanism. In addition to the thermally activated detachment of dislocations from particles, a viscous friction mechanism possibly due to point defect diffusion in the dislocation cores and Taylor hardening contribute to the flow stress.