The Possible transition mechanism for the meta-stable phase in the 7xxx aluminium

Bendo, A.*; Matsuda, Kenji*; Nishimura, Katsuhiko*; Nunomura, Norio*; Tsuchiya, Taiki*; Lee, S.*; Marioara, C. D.*; Tsuru, Tomohito; Yamaguchi, Masatake; Shimizu, Kazuyuki*; et al.

Materials Science and Technology, 36(15), p.1621 - 1627, 2020/09

https://doi.org/10.1080/02670836.2020.1821323

Metastable phases in aluminum alloys are the primary nano-scale precipitates which have the biggest contribution to the increase in the tangible mechanical properties. The continuous increase in hardness in the 7xxx aluminum alloys is associated with the phase transformation from clusters or GP-zones to the metastable phase. The transformation which is structural and compositional should occur following the path of the lowest activation energy. This work is an attempt to gain insight into how the structural transformation may occur based on the shortest route of diffusion for the eventual structure to result in that of phase. However, for the compositional transformation to occur, the proposed mechanism may not stand, since it is a prerequisite for the atoms to be at very precise positions in the aluminum lattice, at the very beginning of structural transformation, which may completely differ from that of the GP-zones atomic arrangements.

Abnormally enhanced diamagnetism in Al-Zn-Mg alloys

Nishimura, Katsuhiko*; Matsuda, Kenji*; Lee, S.*; Nunomura, Norio*; Shimano, Tomoki*; Bendo, A.*; Watanabe, Katsumi*; Tsuchiya, Taiki*; Namiki, Takahiro*; Toda, Hiroyuki*; et al.

Journal of Alloys and Compounds, 774, p.405 - 409, 2019/02

https://doi.org/10.1016/j.jallcom.2018.10.037

Advanced safety of nuclear fuels and cores-systematic approach at the fuel and core subcommittee, 4; Activity on accident tolerance fuels (ATF)

Yamashita, Shinichiro; Abe, Hiroaki*; Sato, Daiki*; Owaki, Masao*; Sakamoto, Kan*; Kusagaya, Kazuyuki*; Tsuchiya, Akiyuki*

no journal, , 

The ATF Working Group (ATF-WG), which started its activities in July 2017, has been considering safety requirements for the introduction of ATF while incorporating overseas knowledge of the United States, which is ahead of ATF development. In the ATF-WG activities, based on the safety design of the core and fuel of LWRs for power generation, we organized the concept of extracting the evaluation items necessary for ATF safety design and the importance of ATF safety. The way of thinking organized here can also be used for the research and development of ATF that are currently underway, and we are going to summarize it in a report in the future.