In Situ HRTEM Observation of Electron-Irradiation-Induced Amorphization and Dissolution of the E(Al18Cr2Mg3) Phase in 7475 Al Alloy
来源期刊：Acta Metallurgica Sinica2015年第2期
论文作者：Mao-Hua Li Yan-Qing Yang Bin Huang Xian Luo Wei Zhang Yan-Xia Chen Ming Han Ji-Gang Ru
文章页码：147 - 151
摘 要：Electron irradiation effects on phase stability of the E（Al18Cr2Mg3） phase have been investigated by highangle annular dark-field scanning transmission electron microscopy and high-resolution transmission electron microscopy（HRTEM）. The in situ HRTEM observations show that the Al18Cr2Mg3 particles with different thickness undergo amorphization and dissolution under 300 ke V electron irradiation at 25 °C. The results indicate that the intermetallic compound Al18Cr2Mg3 is unstable under electron irradiation, and structural changes mainly depend on the thickness of particles. Amorphization in the thick particles is caused by a combination of chemical disordering and an increase in point defect concentration. Dissolution after amorphization in the thin particles is attributed to the diffusion of point defect towards the Al matrix.
Mao-Hua Li1，Yan-Qing Yang1，Bin Huang1，Xian Luo1，Wei Zhang1，Yan-Xia Chen1，Ming Han1，Ji-Gang Ru2
1. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University2. Beijing Institute of Aeronautical Materials
摘 要：Electron irradiation effects on phase stability of the E（Al18Cr2Mg3） phase have been investigated by highangle annular dark-field scanning transmission electron microscopy and high-resolution transmission electron microscopy（HRTEM）. The in situ HRTEM observations show that the Al18Cr2Mg3 particles with different thickness undergo amorphization and dissolution under 300 ke V electron irradiation at 25 °C. The results indicate that the intermetallic compound Al18Cr2Mg3 is unstable under electron irradiation, and structural changes mainly depend on the thickness of particles. Amorphization in the thick particles is caused by a combination of chemical disordering and an increase in point defect concentration. Dissolution after amorphization in the thin particles is attributed to the diffusion of point defect towards the Al matrix.
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