Study on In-situ Heating of Nickel-based Superalloy Irradiated by Xe Ion at Room Temperature

The molten salt reactor has broad prospects as a fourth-generation reactor.UNS N10003 alloy was considered to be the most promising candidate material for molten salt reactors.It would be used for a long time under irradiation, so it is necessary to study the microstructure changes after irradiation.By transmission electron microscopy in-situ heating technology, the evolution of the characteristic structure of UNS N10003 nickel-based alloy after Xe ion irradiation at room temperature was studied.The results show that when the irradiation dose is lower than 0.5 dpa, a large number of black spots appear in the alloy.With the increase of the irradiation dose, the number of black spots in the alloy gradually decreases, and the structural characteristics of light and dark structure are gradually obvious.The typical irradiation characteristics(irradiation dose:0.5 dpa and 10 dpa)were selected for in-situ electron microscopy observation, and it was found that with the temperature increasing, the number of black spots decreases, and the dislocation loop increases; the light and dark structure is gradually destroyed.Black spots are point defects, formed during the irradiation process.These point defects disappear or form dislocation loops at high temperatures; the light-dark structure should be the clustering of defects formed by the irradiation.