Microstructure evolution during electron and ion irradiation in commercial purity magnesium

作者：Khan A K^*; Yao Z; Daymond M R

来源：Philosophical Magazine, 2014, 94(17): 1909-1923.

DOI：10.1080/14786435.2014.899440

• TEM
• ion irradiation
• dislocations

Microstructure evolution during in situ electron irradiation at room temperature within the transmission electron microscope has been studied on commercial purity magnesium. Magnesium foils of purity 99.8% were examined for comparative studies of defect structure formed by 200 keV electrons and 1 MeV krypton ions. Transmission electron microscopy has been used to quantify the type and nature of the microstructural changes taking place during irradiation. Hexagonal- shaped faulted c-component dislocation loops with Burgers vector of 1/6/< 20 (2) over bar(3) over bar > are formed by electron irradiation. Formation of inner un- faulted loops also takes place inside the faulted loops. Analysis shows that all the faulted c- component dislocation loops are interstitial in nature and growth rate of these loops is proportional to the irradiation time. Dislocation loops with Burgers vector 1/3 < 11 (2) over bar0 > also form but most of these loops shrink and disappear during subsequent electron irradiation. In some of the foils, only the pre- existing dislocations in the microstructure were observed to transform into vacancy type 1/3 < 11 (2) over bar0 > loops and helical configurations and no other irradiation damage appeared. Ion irradiation for a dose up to 0.1 dpa produced dislocation loops with Burgers vector of 1/3 < 11 (2) over bar0 > and these loops were mixed vacancy and interstitial in character.

• 出版日期2014