Unusual grain coarsening behavior of bismuth under high pressure
Unusual grain coarsening behavior of bismuth under high pressure
复制标题
高压下铋的异常晶粒粗化行为
DOI：
10.1016/j.matlet.2018.08.016
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发表时间：
2018-12-01
影响因子：
3
通讯作者：
He, Duanwei
中科院分区：
文献类型：
--
作者：
Li, Xin;Yan, Xiaozhi;He, Duanwei
众所周知，高温引起的原子扩散会导致明显的晶粒粗化，这对材料的性能起着至关重要的作用。高压通常会减缓原子的扩散速度，使晶粒尺寸变细。在本研究中，我们利用同步加速器角色散x射线衍射（ADXRD）技术，观察到铋（Bi）在室温下由高压相变引起的异常晶粒粗化行为，表明压力也可以触发晶粒粗化。造成Bi异常粗化行为的主要原因有两个：(1)根据Bi相变动力学研究，在转变过程中，新相的形核速度非常慢，抑制了晶粒的细化；(2)相变过程中的液相使Bi在高压下再结晶。我们的实验结果与前人的理论计算结果一致，这对于描述铋的成核和生长过程以及阐明其相变机制至关重要。(C) 2018 Elsevier B.V.版权所有
It is well known the atomic diffusion caused by high temperature leads to conspicuous grain coarsening, which is of crucial importance to the properties of materials. High pressure usually slows down the diffusion rate of atoms and refines the grain size. In this study, using synchrotron angle dispersive x-ray diffraction (ADXRD) techniques, we observed an abnormal grain coarsening behavior of bismuth (Bi) stemming from the high pressure phase transition at room temperature, demonstrating that the grain coarsening can also be triggered by pressure. Two factors mainly give raise to this unusual coarsening behavior of Bi: (1) the nucleation rate of new phase is very slow during transformation according to the kinetics study of the phase transition in Bi, which inhibits the grain refinement; (2) the liquid interphase in the phase transition process enables the recrystallization of Bi under high pressure. Our experiment results are consistent with the previous theoretical calculations, which is crucial for describing the nucleation and growth process and clarifying the phase transition mechanisms in Bi. (C) 2018 Elsevier B.V. All rights reserved.