Role of thermal stress-driven dislocation and low-angle grain boundary migration in surface plastic deformation and grain orientation evolution of tungsten under thermal shock

作者：Meng-Chong Ren, Yu-Fei Nie, Hanqing Wang, Yue Yuan, Fan Feng, Youyun Lian, Hao Yin, Long Cheng, Duoqi Shi, Guang‐Hong Lu · 发表于：International Journal of Plasticity · 年份：2024 · DOI：10.1016/j.ijplas.2024.104205 · 被引用次数：21 · 研究领域：Microstructure and mechanical properties、High-Velocity Impact and Material Behavior、Advanced materials and composites

• The discovery of grain orientation transitions on the surface of W under cyclic thermal shocks offers new insights for surface treatment techniques. • Cross-sectional EBSD analysis reveals that the depth of these oriented grain orientation transitions can extend to several tens of micrometers, while the resulting surface roughness remains around 1 micrometer. • The microstructural mechanism driving this orientation transition was elucidated using TEM characterization techniques. • The newly formed {110} grain orientation exhibits high-temperature stability (1573 K). • CPFEM simulations were employed to model and predict the grain orientation transitions induced by thermal shocks. This study reveals that thermal fatigue loading (transient thermal shock), similar to that in fusion environments, can serve as a surface processing technique for BCC metals. Regions with a {110} grain orientation can be selectively achieved in varying sizes and locations on the sample surface. Furthermore, our experiments confirm that the specific localized orientation transformation obtained through this method exhibits certain high-temperature stability at 1573 K (above the recrystallization temperature of tungsten). The experiment employed a 0.25 GW/m² high-energy pulsed electron beam for 1 ms to cyclically load the tungsten surface, simulating edge localized mode events in fusion conditions. It was found that tungsten exhibited significant surface grain orientation transformation (distinct {11...