The microstructural evolution of precipitate strengthened copper alloys after varying temperature irradiation

Full text of publication follows: Oxide dispersion strengthened (ODS) copper alloys have been suggested for the fusion applications as diverter heat sink materials since they have high thermal conductivity and high strength. Many studies have been conducted to understand the materials properties of ODS copper alloys under constant irradiation temperature. But irradiation experiments under varying temperature irradiation was very limited. To investigate the effects of varying temperature irradiation on oxide dispersion strengthened copper alloy (GridCop CuAl15), heavy ion irradiation was performed by 2.4 MeV Cu ions up to 30 dpa in the temperature range of 473 K to 673 K. After the periodic temperature irradiation, all samples were thinned by back-thinning method. TEM observation of CuAl15 before irradiation revealed that high density of small alumina particles and dislocations in a grain. After 30 dpa at 673 K constant temperature irradiation, voids formation was also observed after varying temperature irradiation. The number density of void was decreased as compared with that of 673 K constant temperature irradiation. The results of CuAl15 is good agreement with our previous results of pure copper irradiated under same irradiation conditions. (authors)