Si-addition contributes to overcoming the strength-ductility trade-off in high-entropy alloys
Si-addition contributes to overcoming the strength-ductility trade-off in high-entropy alloys
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DOI：
10.1016/j.ijplas.2022.103443
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发表时间：
2022-09
影响因子：
9.8
通讯作者：
Daixiu Wei;W. Gong;T. Tsuru;I. Lobzenko;Xiaoqing Li;S. Harjo;T. Kawasaki;Hyeon-Seok Do;Jae Wung Ba;Christian Wagner;G. Laplanche;Yuichiro Koizumi;H. Adachi;K. Aoyagi;A. Chiba;B. Lee;Hyoung-Seop Kim;Hidemi Kato
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文献类型：
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作者：
Daixiu Wei;W. Gong;T. Tsuru;I. Lobzenko;Xiaoqing Li;S. Harjo;T. Kawasaki;Hyeon-Seok Do;Jae Wung Ba;Christian Wagner;G. Laplanche;Yuichiro Koizumi;H. Adachi;K. Aoyagi;A. Chiba;B. Lee;Hyoung-Seop Kim;Hidemi Kato
含有多主过渡金属的面心立方单相高熵合金（HEA）引起了人们的广泛关注，由于其低堆垛层错能（SFE）和大失配参数（导致严重的局部晶格畸变），表现出前所未有的强度和延展性组合。进一步提高强度和延展性具有挑战性。在本研究中，我们通过细致的实验证明，由于增强的固溶强化和降低的SFE的综合作用，添加替代类金属Si的CoCrFeNi HEA可以保留单相FCC结构，同时其屈服强度（高达65％）、极限强度（高达34％）和延展性（高达15％）同时提高。通过添加硅来调节位错行为和塑性变形机制，从而提高应变硬化和拉伸延展性。本研究提供了通过定向添加非金属来增强 HEA 性能的新策略。
Face-centered cubic single-phase high-entropy alloys (HEAs) containing multi-principal transition metals have attracted significant attention, exhibiting an unprecedented combination of strength and ductility owing to their low stacking fault energy (SFE) and large misfit parameter that creates severe local lattice distortion. Increasing both strength and ductility further is challenging. In the present study, we demonstrate via meticulous experiments that the CoCrFeNi HEA with the addition of the substitutional metalloid Si can retain a single-phase FCC structure while its yield strength (up to 65%), ultimate strength (up to 34%), and ductility (up to 15%) are simultaneously increased, owing to a synthetical effect of the enhanced solid solution strengthening and a reduced SFE. The dislocation behaviors and plastic deformation mechanisms were tuned by the addition of Si, which improves the strain hardening and tensile ductility. The present study provides new strategies for enhancing HEA performance by targeted metalloid additions.