Origin of ultrafast annihilation effect of martensite aging: Atomistic simulations
Origin of ultrafast annihilation effect of martensite aging: Atomistic simulations
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马氏体时效超快湮灭效应的起源：原子模拟
DOI：
10.1103/physrevb.82.184101
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发表时间：
2010-11
影响因子：
3.7
通讯作者：
Ren, Xiaobing
中科院分区：
文献类型：
--
作者：
Suzuki, Tetsuro;Deng, Junkai;Saxena, Avadh;Sun, Jun;Ding, Xiangdong;Lookman, Turab;Otsuka, Kazuhiro;Ren, Xiaobing
在过去的几十年里，注意。已知的是，一旦使老化的马氏体进入母相，甚至在非常短的时间内，即，马氏体时效AEMA的湮灭效应。然而，由于缺乏有效的工具来探测AEMA过程中的原子过程，AEMA的潜在机制仍然不清楚。目前尚不清楚1 AEMA是由单纯的无扩散转变到母相中还是由母相中的扩散过程引起的，以及2为什么马氏体中的长时间时效可以如此容易地在母相中消除。在本文中，我们使用相结合的分子动力学和Monte Carlo模拟表明，AEMA的起源有关的原子在母相中的扩散，而不仅仅是逆相变。B2母相中的开放结构和高温导致母相中的点缺陷的扩散率显著高于马氏体中的点缺陷的扩散率;这解释了马氏体时效的超快湮灭。我们将AEMA的驱动力归因于点缺陷的有序化趋势。
attention in the past decades. It is known that martensite aging effects can be quickly eliminated once the aged martensite is brought into the parent phase even for a very short time, i.e., the annihilating effect of martensite aging AEMA. However, the underlying mechanism of AEMA remains unclear due to the lack of an effective tool to probe the atomic processes during AEMA. It is unclear 1 whether AEMA is caused by a mere diffusionless transformation into the parent phase or by a diffusional process in the parent phase and 2 why long-time aging in martensite can be so easily eliminated in the parent phase. In this paper we use combined molecular-dynamics and Monte Carlo simulations to show that the origin of AEMA is related to atomic diffusion in the parent phase, not merely the reverse phase transformation. The open structure in the B2 parent phase and high-temperature result in a significantly higher diffusivity of point defects in the parent phase compared with that in the martensite; this explains the ultrafast annihilation of martensite aging. We attribute the driving force of AEMA to the symmetry-conforming short-range ordering tendency of point defects.