Microstructure and properties of pure zirconium after irradiation by charged particles

Abstract

In order to estimate the possible application of zirconium-based alloy in space craft, the space irradiation effects have been studied using ground simulation testing of a model material, pure zirconium, in this paper. The irradiation tests of charged particles such as protons, argon ion and nitrogen ion on a pure zirconium, UNS R60702 (denoted as Zr 702 herewith), was carried out in a ground space simulation irradiation facility. X-ray diffractometry (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Nanoindentation, dynamic mechanical analyzis (DMA) and tensile testing were employed to examine the microstructure and properties of the proton, nitrogen ion or argon ion irradiated Zr 702. It is shown that after irradiation with 120 keV protons and argon or nitrogen ions, the specimen surface morphology practically did not change and no new phases could be detected within the surface layer of Zr 702. Dislocation configurations in the irradiated region of Zr 702 were however affected by proton and nitrogen and argon ion irradiation. The bulk mechanical properties such as tensile strength and fracture strain of Zr 702 were mostly not influenced by 120 keV protons and argon or nitrogen ion irradiation. The local properties such as nano-hardness of the irradiated surface were found to vary with the fluence or type of the charged particles.