In Situ HRTEM Observation of Electron-Irradiation-Induced Amorphization and Dissolution of the E(Al_(18)Cr_2Mg_3) Phase in 7475 Al Alloy  

作　　者：Mao-Hua Li Yan-Qing Yang Bin Huang Xian Luo Wei Zhang Yan-Xia Chen Ming Han Ji-Gang Ru 

机构地区：[1]State Key Laboratory of Solidification Processing, Northwestern Polytechnical University [2]Beijing Institute of Aeronautical Materials

出　　处：《Acta Metallurgica Sinica(English Letters)》2015年第2期147-151,共5页金属学报（英文版）

基　　金：financially supported by the 111 Project (No. B08040) of China;National Natural Science Foundation of China (No. 51071125)

摘　　要：Electron irradiation effects on phase stability of the E （Al18Cr2Mg3） phase have been investigated by high- angle annular dark-field scanning transmission electron microscopy and high-resolution transmission electron microscopy （HRTEM）. The in situ HRTEM observations show that the Ala8Cr2Mg3 particles with different thickness undergo amorphization and dissolution under 300 keV electron irradiation at 25 ℃. 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.Electron irradiation effects on phase stability of the E （Al18Cr2Mg3） phase have been investigated by high- angle annular dark-field scanning transmission electron microscopy and high-resolution transmission electron microscopy （HRTEM）. The in situ HRTEM observations show that the Ala8Cr2Mg3 particles with different thickness undergo amorphization and dissolution under 300 keV electron irradiation at 25 ℃. 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.

关 键 词：Intermetallic compound Al18Cr2Mg3 Irradiation effects Amorphization DISSOLUTION 

分 类 号：TG146.21[一般工业技术—材料科学与工程]