Impact of irradiation on the microstructure of nanocrystalline materials

Nanostructured materials should present a good resistance to irradiation because the large volume fraction of grain boundaries can be an important sink for radiation-induced defects. The objective of the present study is to experimentally investigate the irradiation impact on the microstructure in nanostructured materials. Nickel and Cu–0.5A2O3 specimens were synthesized by electro deposition (ED) and severe plastic deformation (SPD). 590 MeV proton irradiation was conducted in the Proton IRradiation EXperiment facility (PIREX). ED Ni were also irradiated in Tandem type accelerator with Ni+ ions of 840 keV. The irradiation induced microstructure, which leads to hardening, consists exclusively of stacking fault tetrahedra. Their density appears much lower than in the case of coarser grained material. In order to assess the change in grain size induced by irradiation, annealing experiments have been performed. These results, experimentally showing the resistance of nanostructured material to radiation damage, are presented here.