Metalloid substitution elevates simultaneously the strength and ductility of face-centered-cubic high-entropy alloys
Metalloid substitution elevates simultaneously the strength and ductility of face-centered-cubic high-entropy alloys
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DOI：
10.1016/j.actamat.2021.117571
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发表时间：
2021-12
期刊：
影响因子：
9.4
通讯作者：
Daixiu Wei;Liqiang Wang;Yongjie Zhang;W. Gong;T. Tsuru;I. Lobzenko;Jianzhong Jiang;S. Harjo;T. Kawasaki;J. Bae;Weidong Lu;Zhen-Ming Lu;Y. Hayasaka;T. Kiguchi;N. Okamoto;T. Ichitsubo;Hyoung-Seop Kim;T. Furuhara;E. Ma;H. Kato
中科院分区：
文献类型：
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作者：
Daixiu Wei;Liqiang Wang;Yongjie Zhang;W. Gong;T. Tsuru;I. Lobzenko;Jianzhong Jiang;S. Harjo;T. Kawasaki;J. Bae;Weidong Lu;Zhen-Ming Lu;Y. Hayasaka;T. Kiguchi;N. Okamoto;T. Ichitsubo;Hyoung-Seop Kim;T. Furuhara;E. Ma;H. Kato
近年来开发的含有多种主要金属元素的高熵合金（HEAs）扩展了固溶体的组成空间和力学性能范围。在这里，我们展示了通过用类金属代替组成金属可以进一步扩大可能性的领域，这是定制强度/延展性所需要的，因为它们具有化学相互作用和原子大小明显不同于主金属元素。具体来说，类金属取代增加了局部晶格畸变和短程化学不均匀性，从而提高了强度，同时降低了层错能，阻碍了动态恢复，并通过部分位错介导的活动促进了缺陷的积累。这赋予了有效的位错储存，以提高应变硬化能力，这是维持大拉伸伸长率所必需的。因此，类金属取代HEAs避免了通常预期的强度和延展性之间的权衡，使这些单相固溶体具有高拉伸强度和非凡延展性的不同寻常的协同作用。
Recently-developed high-entropy alloys (HEAs) containing multiple principal metallic elements have extended the compositional space of solid solutions and the range of their mechanical properties. Here we show that the realm of possibilities can be further expanded through substituting the constituent metals with metalloids, which are desirable for tailoring strength/ductility because they have chemical interactions and atomic sizes distinctly different from the host metallic elements. Specifically, the metalloid substitution increases local lattice distortion and short-range chemical inhomogeneities to elevate strength, and in the meantime reduces the stacking fault energy to discourage dynamic recovery and encourage defect accumulation via partial-dislocation-mediated activities. These impart potent dislocation storage to improve the strain hardening capability, which is essential for sustaining large tensile elongation.As such, metalloid substitution into HEAs evades the normally expected strength-ductility trade-off, enabling an unusual synergy of high tensile strength and extraordinary ductility for these single-phase solid solutions.