论文标题

电子对高渗透合金辐射损伤的影响

Electronic effects on the radiation damage in high-entropy alloys

论文作者

Orhan, Okan K., Hendy, Mohamed, Ponga, Mauricio

论文摘要

高渗透合金(HEAS)是由于其复杂的局部化学环境和缓慢的缺陷迁移而是抗辐射材料的特殊候选物。尽管通常被忽略了,但电子对辐射环境中缺陷进化的影响也通过通过电子波耦合和级联事件期间的电子热传导来消除多余的能量,从而发挥着至关重要的作用。我们介绍了四个和五个主元素中随机固体溶液(RSS)中电子特性的系统研究,及其对缺陷形成,聚类和重组的影响。电子特性,包括电子偶联因子,电子特异性热和电子导热率,在第一原理计算中计算。使用两个温度的分子动力学模拟,我们表明电子 - 音波耦合因子和电子特异性热在Frenkel对形成中起关键作用。具体而言,电子 - 音波耦合因子通过等离子体激发迅速在原子原子事件期间迅速消散动能,随后通过自由电子传导消散。我们表明,这些影响比原子不匹配产生的弹性失真效应更为关键。引人注目的是,我们表明,包括较轻的元素有助于增加电子偶联因子,这表明通过最佳组成提高HEA中的辐射耐性的可能性。

High-entropy alloys (HEAs) are exceptional candidates for radiation-resistant materials due to their complex local chemical environment and slow defect migration. Despite commonly overlooked, electronic effects on defects evolution in radiation environments also play a crucial role by dissipating excess energy through electron-phonon coupling and electronic heat conduction during cascade events. We present a systematic study on electronic properties in random-solid solutions (RSS) in four and five principal elements HEAs and their effect on defect formation, clustering, and recombination. Electronic properties, including electron-phonon coupling factor, the electronic specific heat, and the electronic thermal conductivity, are computed within first-principles calculations. Using the two-temperature molecular dynamics simulations, we show that the electron-phonon coupling factor and electronic specific heat play a critical role in Frenkel pairs formation. Specifically, the electron-phonon coupling factor quickly dissipates the kinetic energy during primary knock-on atom events via plasmon excitations and is subsequently dissipated via the free-electrons conduction. We show that these effects are more critical than the elastic distortion effects produced by the atomic mismatch. Of tremendous interest, we show that including lighter elements helps to increase the electron-phonon coupling factor, suggesting the possibility to improve radiation resistance in HEA through optimal composition.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源