Hardness and electrical resistivity of molybdenum in the post-irradiated and annealed conditions

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

“…Indeed, it is in agreement with the appearance of the damping peak in the mechanical spectroscopy tests during the cooling, after an annealing to 973 K (stage V) [15,23]. At temperatures higher than 1000 K, the DTA curve seems to develop another exothermic reaction related to a further recovery of the irradiated structure at higher temperatures [10,14,15]. A further recovery of the radiation damage at temperatures higher than 1223 K has been also reported earlier in the literature [14][15][16].…”

“…At temperatures higher than 1000 K, the DTA curve seems to develop another exothermic reaction related to a further recovery of the irradiated structure at higher temperatures [10,14,15]. A further recovery of the radiation damage at temperatures higher than 1223 K has been also reported earlier in the literature [14][15][16].…”

“…In addition, a stage (plateau) around 1000 K appears and subsequently at higher temperatures the ER starts to decrease again. As it was recently explained [15], the increase in the ER values from 300 K up to 600 K, coincides with the stage III of recovery in irradiated samples; which was related to the movement of vacancies [8,10,14]. It has been reported that in neutron irradiated molybdenum at room temperature, a subsequent annealing at temperatures between 473 K and 573 K produces an increase in the yield stress and in the ultimate tensile strength (UTS) [8], due to the appearance of internal stresses within the temperature range of the stage III [15].…”

“…The appearance of five stages of recovery has been proposed 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 [3,8,10,14]. For instance, in stage III, it has been reported that in neutron irradiated molybdenum at room temperature, a subsequent annealing at temperatures between 473 K and 573 K lead to an increase in the yield stress and in the ultimate tensile strength (UTS); which is promoted by the movement of vacancies [8,10,14].…”

“…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 [3,8,10,14]. For instance, in stage III, it has been reported that in neutron irradiated molybdenum at room temperature, a subsequent annealing at temperatures between 473 K and 573 K lead to an increase in the yield stress and in the ultimate tensile strength (UTS); which is promoted by the movement of vacancies [8,10,14]. Besides this, in mechanical spectroscopy tests, it was found that annealing at temperatures of the stage V is required for restoring the characteristic of the damping peak related to the dragging of jogs by the dislocation under movement assisted by vacancy diffusion [15].…”