高熵合金的力学性能及变形行为研究进展

李建国; 黄瑞瑞; 张倩; 李晓雁

doi:10.6052/0459-1879-20-009

高熵合金的力学性能及变形行为研究进展

doi: 10.6052/0459-1879-20-009

清华大学工程力学系, 北京 100084

基金项目: 1)国家自然科学基金;北京市自然科学基金(Z180014);国家科技重大专项(2017-VI-0003-0073)

详细信息

通讯作者:
李晓雁

中图分类号: O341
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出版历程
- 收稿日期: 2020-01-09
- 刊出日期: 2020-04-10

MECHNICAL PROPERTIES AND BEHAVIORS OF HIGH ENTROPY ALLOYS

Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China

摘要

摘要: 高熵合金是近年来提出的一种新的合金设计理念,打破了一般合金中以1种或2种元素为主,辅以极少量其他元素来改善合金性能的传统思想,由多种元素以等原子或近似等原子比混合后形成具有独特原子结构特征的单一固溶体合金.高熵合金的多主元特性使其在变形过程中表现出多重机制(包括位错机制、形变孪生、相变等)的协同,因而高熵合金已经展示了优异的力学性能,如高强、高硬、高塑性、抗高温软化、抗辐照、耐磨等,被认为是最具有应用潜力的新型高性能金属结构材料,已经成为国际固体力学和材料科学领域研究的热点.本文首先介绍了高熵合金独特的结构特征, 即具有短程有序结构和严重的晶格畸变;随后对近年来针对不同类型高熵合金(包括具有面心立方相、体心立方相、密排六方相、多相以及亚稳态高熵合金)力学性能、变形行为方面的研究成果,特别是强韧化机制以及相关的原子尺度模拟, 进行了较为系统的综述;最后强调了高熵合金未来研究中所面临的一些主要问题和挑战,并对其研究进行了展望.
- 高熵合金 /
- 力学性能 /
- 变形机理 /
- 强韧化 /
- 原子尺度模拟
Abstract: High-entropy alloys (HEAs) are a class of new metallic materials that have revolutionized alloy design over the past ten years. Unlike conventional alloys with one and rarely two base elements, HEAs contain multiple principal elements (at least four principal elements) with equal or nearly equal atomic concertation to promote the formation of simple solid solution phases. Due to the presence of multiple principal elements, multiple deformation mechanisms (including dislocation activities, deformation twinning, and phase transformation) activate during deformation of HEAS. Therefore, HEAs usually exhibited many excellent mechanical properties, such as ultrahigh hardness, high tensile strength, good ductility, high thermal softening resistance, remarkable irradiation resistance, and good wear resistance. HEAs are thought to be the most promising structure materials and have attracted tremendous attention over worldwide in the fields of solid mechanics and material sciences. In this review paper, we first briefly introduce the unique and complicated microstructural features of HEAs, i.e. HEAs have both chemically short-range orderings and severe lattice distortion. Then, we review the recent experimental studies on mechanical properties, behaviors and deformation mechanisms of HEAs with face-centered cubic, body-centered cubic, hexagonal close-packed, dual or meta-stable phases. We also mainly emphasize some effective strengthening and toughening strategies, including solid solution, grain refinement, second phase or precipitation. We further summarize some advanced atomistic simulations/modelling on microstructures, mechanical properties and deformation of various HEAs. Finally, we address a list of open problems and challenges for the future studies about design, fabrication and mechanics of HEAs, and provide some important mechanistic insights into design and fabrication of HEAs with excellent mechanical properties and performances.
- high entropy alloy /
- mechanical properties /
- deformation mechanisms /
- strengthening and toughening /
- atomistic simulations

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