温度对 FeCoNiCrMn 高熵合金塑性变形影响的分子动力学研究

Molecular dynamics research of temperature effect on plastic deformation of FeCoNiCrMn high-entropy alloy

摘要

对单晶与多晶 FeCoNiCrMn 高熵合金、单晶与多晶 Ni 这 4 种模型微结构演化受温度依赖性研究有助于理解塑性变形微观机制。本工作基于纳米压痕法，重点比较分析极端低温（1 K）到极端高温（1300 K）变化对单晶与多晶 FeCoNiCrMn 高熵合金、单晶与多晶 Ni 的塑性变形微结构演化、原子位移幅度、剪切变形、位错总长和 von Mises 应力分布的影响。结果表明：从极端低温（1 K）升高到极端高温（1300 K），单晶 FeCoNiCrMn 高熵合金、单晶 Ni、多晶 FeCoNiCrMn 高熵合金和多晶 Ni 的最大载荷下降幅度分别为 37.69%、29.10%、55.06% 和 15.64%。由于多晶 FeCoNiCrMn 高熵合金和多晶 Ni 晶界存在缺陷，晶界处高应力集中诱导位错在晶界边缘处形核与增殖。受纳米压痕载荷诱导的 4 种模型塑性变形微结构演化以堆垛层错、孪晶、非晶及相变转化协同作用为主：单晶 FeCoNiCrMn 高熵合金塑性变形产生类鼓包状结构，限制位错滑移与扩张；单晶 Ni 塑性变形产生的位错滑移现象较突出；相比于多晶 Ni，多晶 FeCoNiCrMn 高熵合金塑性变形产生的无定型非晶层更厚，位错总长更小，这一趋势受极端低温到高温的变化影响小。多晶 FeCoNiCrMn 高熵合金和多晶 Ni 塑性变形均发生晶界的迁移与扩张，为更细纳米晶结构的形成创造有利条件。这些研究结果在研发优异强韧化性能的高熵合金体系方面具有重要理论参考价值。

Abstract

Studies on the temperature dependence of microstructure evolution for four models， namely single crystal and polycrystalline FeCoNiCrMn high-entropy alloys as well as single crystal and polycrystalline Ni，help elucidate the microscopic mechanisms of plastic deformation. Based on the nanoindentation method，this work focuses on comparative analysis of the effects of temperature variation from an extremely low temperature (1 K) to an extremely high temperature (1300 K) on the plastic deformation microstructure evolution，atomic displacement magnitude，shear deformation，total dislocation length，and von Mises stress distribution of single crystal and polycrystalline FeCoNiCrMn high-entropy alloys， together with single crystal and polycrystalline Ni. The results show that when the temperature rises from 1 K to 1300 K，the maximum load decreases by 37.69%，29.10%，55.06%，and 15.64% for single crystal FeCoNiCrMn high-entropy alloy，single crystal Ni，polycrystalline FeCoNiCrMn high-entropy alloy，and polycrystalline Ni，respectively. Defects exist at grain boundaries in polycrystalline FeCoNiCrMn high-entropy alloy and polycrystalline Ni；high stress concentration at grain boundaries induces dislocation nucleation and proliferation at grain boundary edges. The plastic deformation microstructure evolution of the four models under nanoindentation loading is dominated by the synergistic effect of stacking faults，twins，amorphous phases，and phase transformation：plastic deformation of single crystal FeCoNiCrMn high-entropy alloy generates bulge-like structures that restrain dislocation slip and propagation；prominent dislocation slip is observed in plastically deformed single-crystal Ni. Compared with polycrystalline Ni，polycrystalline FeCoNiCrMn high-entropy alloy forms thicker amorphous layers and exhibits shorter total dislocation length during plastic deformation，and this trend is weakly affected by temperature change from cryogenic to high temperature. Grain boundary migration and expansion occur in both polycrystalline FeCoNiCrMn high-entropy alloy and polycrystalline Ni during plastic deformation，which facilitates the formation of finer nanocrystalline structures. These findings provide important theoretical references for developing high-entropy alloy systems with outstanding strength-toughness synergy.

关键词

极端温度 / FeCoNiCrMn 高熵合金 / 塑性变形 / 纳米压痕 / 分子动力学

Key words

extreme temperature / FeCoNiCrMn high-entropy alloy / plastic deformation / nanoindentation / molecular dynamics

参考文献

[1] Fu W J，Huang Y J，Sun J F，et al. Strengthening CrFe—CoNiMn_0.75Cu_0.25 high entropy alloy via laser shock peening[J].International Journal of Plasticity， 2022，154：103296.

[2] Tran N D，Saengdeejing A，Suzuki K，et al. Stability and thermodynamics properties of CrFeNiCoMn/Pd high entropy alloys from first principles[J].Journal of Phase Equilibria and Diffusion，2021，42（5）：606.

[3] Li C， Xue Y F， Hua M T， et al. Microstructure and mechanical properties of Al_xSi_0.2CrFeCoNiCu_1—x high—entropy alloys[J].Materials and Design，2016，90：601-609.

[4] Du X，Lu X C，Shuang S Y，et al. Cyclic plasticity of CoCrFeMnNi high—entropy alloy （HEA）： a molecular dynamics simulation[J].International Journal of Applied Mechanics，2021，13：2150006.

[5] Wan C K，Yuan J C，Li L X，et al. Dynamic compression of dendritic high—entropy alloy Al_0.5CoCrFeNi with various microstructures：experiments and constitutive modeling[J].Materials Science & Engineering A，2025，930：148117.

[6] 陈晶晶，占慧敏，吴昊，等. 纳米晶 CoNiCrFeMn 高熵合金的拉伸力学性能[J].材料研究学报，2023，37（8）：614-624.

[7] Chen J J，Zhan H M，Wu H，et al. Tensile mechanical performance of high entropy nanocrystalline CoNiCr—FeMn alloy[J].Chinese Journal of Materials Research，2023，37（8）：614-624.

[8] Zhao C D，Li J S，Liu Y D，et al. Optimizing mechanical and magnetic properties of AlCoCrFeNi high—entropy alloy via FCC to BCC phase transformation[J].Journal of Materials Science & Technology，2021，86：117-126.

[9] 孟易辰，褚胤闰，石岳林，等. 激光熔覆 CoCrNi 系中高熵合金的摩擦学和电化学性能研究[J].稀有金属材料与工程，2025，54（4）：983-992.

[10] Meng Y C，Chu Y R，Shi Y L，et al. Tribological and electrochemical properties of CoCrNi—based medium and high entropy alloys prepared by laser cladding[J].Rare Metal Materials and Engineering，2025，54（4）：983-992.

[11] Afkham Y，Bahramyan M，Mousavian R T，et al. Tensile properties of AlCrCoFeCuNi glassy alloys：a molecular dynamics simulation study[J].Materials Science and Engineering：A，2017，698：143-151.

[12] Ding L，Wang H X，Quan X M. Microstructure and abrasion resistance of laser cladding CoCrFeNiTiNbB_1.25 high—entropy alloys coatings treated by aging[J].Science of Advanced Materials，2021，13（8）：1479-1487.

[13] Guo T，Wu L P，Li T. Machine learning accelerated，high throughput， multi—objective optimization of multiprincipal element alloys[J].Small，2021，17（42）：2102972.

[14] Gali A， George E P. Tensile properties of high— and medium—entropy alloys[J].Intermetallics，2013，39：74-78.

[15] Huang S， Li W， Lu S， et al. Temperature dependent stacking fault energy of FeCrCoNiMn high entropy alloy[J].Scripta Materialia，2015，108：44-47.

[16] Qiao J W，Ma S G，Huang E W，et al. Microstructural characteristics and mechanical behaviors of AlCoCrFeNi high—entropy alloys at ambient and cryogenic temperatures[J].Materials Science Forum，2011，688：419-425.

[17] 陈晶晶，邱小林，李柯，等. 纳米晶 CoNiCrFeMn 高熵合金力学性能的原子尺度分析[J].物理学报，2022，71（19）：199601.

[18] Chen J J，Qiu X L，Li K，et al. Mechanical performance analysis of nanocrystalline CoNiCrFeMn high entropy alloy： atomic simulation method[J].Acta Physica Sinica，2022，71（19）：199601.

[19] 黄伟玲，陈晶晶. 多晶 CoNiCrFeMn 高熵合金塑性变形原子尺度分析[J].材料导报，2021，35（24）：24107-24112.

[20] Huang W L， Chen J J. Atomic mechanism of plastic deformation for poly—crystalline CoNiCrFeMn high entropy alloy[J].Materials Reports， 2021， 35（24）：24107-24112.

[21] Chen S，Aitken Z H，Pattamatta S，et al. Simultaneously enhancing the ultimate strength and ductility of high—entropy alloys via short—range ordering[J].Nature Communications，2021，12：4953.

[22] Wu Y C， Shao J L ， FCC—BCC phase transformation induced simultaneous enhancement of tensile strength and ductility at high strain rate in high—entropy alloy[J].International Journal of Plasticity，2023，169：103730.

[23] Zhang Z，Jiang Z H，Xie Y H，et al. Multiple deformation mechanisms induced by pre—twinning in CoCrFeNi high entropy alloy[J].Scripta Materialia， 2022， 207：114266.

[24] Plimpton S. Fast parallel algorithms for short—range molecular dynamics[J].Journal of Computational Physics，1995，117（1）：1-19.

[25] Dong B，Wang X M，Zhu Z L. Study on the mechanical performance and microstructure of FeCoCrCuNi high—entropy alloy with crack and void by molecular dynamics simulations[J].Journal of Atomic and Molecular Physics，2020，37：591.

[26] Fang Q H，Chen Y，Li J，et al. Probing the phase transformation and dislocation evolution in dual—phase high—entropy alloys[J].International Journal of Plasticity，2019，114：161-173.

[27] Foiles S M， Baskes M I， Daw M S. Embedded—atom—method functions for the FCC metals Cu，Ag，Au，Ni，Pd， Pt， and their alloys[J].Physical Review B， 1986，33（12）：7983-7991.

[28] Guo J， Chen J J， Wang Y Q. Temperature effect on mechanical response of c—plane monocrystalline gallium nitride in nanoindentation： a molecular dynamics study[J].Ceramics International，2020，46（8）：12686-12694.

[29] Chen J J，Wu H，Bai S H，et al. Response of mechanical properties and subsurface damage in β—SiC to temperature and crystal plane during nanoindentation simulation[J].Materials Science in Semiconductor Processing，2023，165：107651.

[30] Wang K Y， Cheng Z J， Liu C Y， et al. Deformation behavior and strengthening mechanisms of high—entropy alloys under high strain rate across wide temperature ranges[J].International Journal of Plasticity，2025，189：104321.

基金资助

国家自然科学基金(62563030)

江西省教育厅科学技术研究项目(GJJ2402616)

江西省教育厅科学技术研究项目(GJJ2502610)