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Updated: Jun 18, 2025

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在多元元素合金中普遍存在的短距离顺序

Ying Han¹, Hangman Chen², Yongwen Sun¹

¹Department of Engineering Science and Mechanics and Materials Research Institute, The Pennsylvania State University, University Park, PA, USA.

Nature communications

|August 1, 2024

概括

短程顺序 (SRO) 是多主元素合金 (MPEA) 的固有特征. 它在固化过程中的形成是快速的,并且在很大程度上独立于加工条件,这挑战了SRO工程的努力.

科学领域:

材料科学材料科学材料科学
金工业是金工业的一个方面.
计算材料科学科学计算材料科学

背景情况:

短程订单 (SRO) 显著影响多主元素合金 (MPEA) 的性能.
了解和控制SRO形成机制对于推进MPEA工程至关重要.
目前关于SRO形成及其在MPEA中精确控制的知识仍然有限.

研究的目的:

研究基于CoCrNi的面部中心立方体 (FCC) MPEAs中SRO的形成和特征.
阐明加工参数,特别是冷却速度对SRO发展的影响.
确定合金固化过程中SRO形成的基本机制.

主要方法:

利用先进的增材制造来制造MPEA样品,覆盖广泛的冷却速率 (高达10^7 K/s).
采用增强的半定量电子显微镜技术进行详细的SRO表征.
在极端冷却条件下 (高达10^11 K/s) 在液体-固体接口上进行原子模拟以建模SRO形成.

主要成果:

在基于CoCrNi的FCC MPEAs中观察到一致的SRO水平,无论处理历史和热处理.
原子学模拟表明,局部化学秩序在固化前线迅速形成.
超冷液相中的原子扩散被发现与固化速率相当或比它更快,即使在极高的冷却速率下也是如此.

结论:

短期订单是大多数FCCMPEA的内在属性,在固化过程中固然形成.
对于冷却速率和回火处理的实验变化,SRO形成在很大程度上是不敏感的.
这些发现表明,MPEA中的SRO工程可能需要超出传统处理修改的方法.

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