Microstructural Responses of Alloy 625 and Alloy 625 Plus Under Ion and Proton Irradiations

Ion- and proton-irradiated Ni-based alloys, Alloy 625 and Alloy 625 Plus, in the as-quenched and aged conditions, were investigated to understand the precipitation behavior under irradiation. Ion irradiations led to randomization of solute distributions while precipitation of the Pt2Mo-type ordered phase, solute clustering and solute segregation to dislocation loops were observed after proton irradiations. In addition, pre-existing γ″ precipitates dissolved under proton irradiation in Alloy 625, while they appeared stable in Alloy 625 Plus. The irradiated microstructures were independent of the starting conditions (as-quenched or aged) and appeared to converge to the same steady state for a given irradiation condition.