Study of the temperature evolution of defect agglomerates in neutron irradiated molybdenum single crystals

Dislocations and point defects in neutron irradiated single crystalline Mo at elevated temperatures

“…In contrast, the peak at high-T was related to movement of dislocations controlled by the formation and diffusion of vacancies assisted by the dislocation movement [1,3]. The damping response in the MS tests is in agreement with that exhibited by the ER, DTA (Fig.…”

“…3 ) and SANS studies. Indeed, the increase in the ER values from 300 K up to 600 K in both 110 and 149 samples, coincides with the stage III in irradiated samples, which was related both to the movement of vacancies and to the appearance of internal stresses [1,3]. In fact, the appearance of five stages of recovery has been proposed for molybdenum depending of their temperature range.…”

“…In fact, the appearance of five stages of recovery has been proposed for molybdenum depending of their temperature range. They can be defined as stage I, below 120 K; stage II, from 120 K to 330 − 350 K; stage III, from 330 − 350 K to 600 K; stage IV, from 600 K to 850 − 900 K and stage V, for temperatures higher than 850 − 900 K [2,3,4,5,6,7]. Stages I and II are attributed to migration of interstitials, meanwhile stage III is attributed to the movement of vacancies.…”

“…Therefore, the appearance of internal stresses in stage III, due to the reorganization of defects out of thermodynamic equilibrium, leads to the locking of dislocations during the first run-up in temperature in the MS test. It gives rise to the damping background, which is amplitude dependent [1,3], without the appearance of the damping peak (curves A and D, during the first heating run in Figs. 1 and 2).…”

“…After plastic deformation samples were irradiated with neutrons (dose < 10 −5 dpa) at RT, at the nuclear reactor RA-4, UNR-CNEA, Argentina [1]. The details for MS, ER, DTA, TEM and SANS (D11, ILL, Grenoble, France) measurements are given elsewhere [1,3].…”