Irradiation damage in commercial purity magnesium

Abstract In-situ electron irradiation damage within the transmission electron microscope has been studied and compared with ion irradiation on commercial purity magnesium. Magnesium has the same crystal structure (hcp) and a similar c/a ratio to that of zirconium and is considered a suitable model system and useful analogue to zirconium (an important structural material for nuclear reactors). The results presented in this paper suggest that microstructure developed during irradiation is modified by the nature of the irradiating particles. The basal plane dislocation loops with Burgers vector 1 / 6 〈 2 0 2 ¯ 3 〉 are formed by electron irradiation and analysis showed that all of these dislocation loops are interstitial in nature. Vacancy type prism plane dislocation loops with Burgers vector 1 / 3 〈 1 1 2 ¯ 0 〉 also form but to a lesser degree than the basal plane dislocation loops. Ion irradiation for a dose up to 0.1 dpa produces a majority of interstitial type prism plane dislocation loops with Burgers vector 1 / 3 〈 1 1 2 ¯ 0 〉 . Void formation also takes place in ion irradiated samples subjected to a higher dose of 0.7 dpa.