Microstructure evolution of zircaloy-4 during Ne ion irradiation and annealing： An in situ TEM investigation

• Published in: Chinese physics B 2014-03, Vol.23 (3), p.441-445
• Main Author: 申华海 彭述明 周晓松 孙凯 王鲁闽 祖小涛
• Format: Article
• Language: English
• Subjects: Annealing; Density; Evolution; Ion irradiation; Nanocrystals; Precipitates; Precipitation; Recrystallization; Zirconium base alloys; Zr-4合金; 位错密度; 原位透射电镜; 离子辐照; 纳米晶体; 组织演变; 退火温度; 退火过程
• ISSN: 1674-1056; 2058-3834; 1741-4199
• DOI: 10.1088/1674-1056/23/3/036102

The microstructural evolution of zircaloy-4 was studied, including the amorphization and recrystallization of Zr（Fe, Cr）2 precipitates, and the density of dislocations under in situ Ne ion irradiation and post annealing. The results show that irradiation at a relatively high temperature and dose induces the formation of nanocrystals in pre-amorphized Zr（Fe, Cr）2 precipitates. The recrystallized nanocrystals also have the structure of hcp-Zr（Fe, Cr）2. The formation of the nanocrystals is thought to be the consequence of competition between atomistic disordering and the recrystallization of precipitates under ion irradiation. The free energy of the nanocrystal is lower than that of the amorphous state, which is another reason for the recrystallization of the precipitates. With increased annealing temperature, the density of the nanocrystals is increased. The dislocation density sharply decreases with the increase in the annealing temperature, and its size increases.