Popov Dmitry, Velisavljevic Nenad, Liu Wenjun, Hrubiak Rostislav, Park Changyong, Shen Guoyin
High Pressure Collaborative Access Team, X-ray Science Division, Argonne National Laboratory, Lemont, Illinois, USA.
Shock and Detonation Physics Group, Los Alamos National Laboratory, Los Alamos, New Mexico, USA.
Sci Rep. 2019 Oct 31;9(1):15712. doi: 10.1038/s41598-019-51992-2.
We report a synchrotron Laue diffraction study on the microstructure evolution in zirconium (Zr) as it undergoes a pressure-driven structural phase transformation, using a recently developed real time scanning x-ray microscopy technique. Time resolved characterizations of microstructure under high pressure show that Zr exhibits a grain enlargement across the α-Zr to ω-Zr structural phase transition at room-temperature, with nucleation and growth of ω-Zr crystals observed from initially a nano-crystalline aggregate of α-Zr. The observed grain enlargement is unusual since the enlargement processes typically require substantially high temperature to overcome the activation barriers for forming and moving of grain boundaries. Possible mechanisms for the grain enlargement are discussed.
我们报告了一项关于锆（Zr）在压力驱动的结构相变过程中微观结构演变的同步辐射劳厄衍射研究，采用了最近开发的实时扫描X射线显微镜技术。高压下微观结构的时间分辨表征表明，在室温下，Zr从α-Zr到ω-Zr的结构相变过程中呈现出晶粒长大现象，观察到ω-Zr晶体从最初的α-Zr纳米晶聚集体中形核并生长。观察到的晶粒长大现象不同寻常，因为这种长大过程通常需要相当高的温度来克服形成和移动晶界的激活能垒。文中讨论了晶粒长大的可能机制。
