Liangbin Chen a , Ke Tang b, ⁎ , Weijie Tian a , Ran Wei c , Yaohui Li a , Yanpu Chao a , Feng Jiang b, ⁎

a School of Mechatronics Engineering, Xuchang University, Xuchang, 461000, China

b State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an,

710049, China

c School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, China

 

摘要： 

大量碳掺杂是提升面心立方（FCC）中/高熵合金（M/HEAs）力学性能的有效策略，但常会在低温环境下诱发延性-脆性转变（DBT），从而限制其低温应用。本研究制备了(Fe40Mn40Co10Cr10)96.7C3.3多元素合金（MEA），并在室温下进行冷轧处理以预先引入微观结构变形，避免低温 DBT 行为。此外，系统研究了冷轧减量与温度对力学响应、变形机制及断裂特性的影响。研究结果表明，该MEA在冷轧及后续拉伸变形过程中始终保持单一FCC相结构且未发生相变。在298 K温度下，合金表现出典型的强度-延展性特性：屈服强度从476 MPa线性增至1279 MPa，断裂伸长率从70.1%降至12.6%，同时断裂模式随冷轧减薄率增加从剪切断裂转变为正断裂。相比之下，在77 K温度下，该合金表现出非单调的延展性演变，即断裂伸长率从冷轧20%时的降至12.7%，但在30%轧制量时升至26.5%，从而实现优异的强度-延展性协同效应（屈服强度：1625 MPa）。这种现象源于变形孪晶的广泛激活作用——这些孪晶不仅能承载塑性应变，还能抑制应变集中效应，从而将断裂模式从晶间断裂有效转变为跨晶断裂。对强化机制的定量分析表明，位错强化与孪晶边界强化是影响屈服强度的主要因素。本研究证实，适时施加预变形是调控变形机制、抑制碳掺杂金属/合金高强钢低温脆性的有效策略。

 

 

本文是在2018年首次发表的MSEA论文工作的继续，主要是开发低成本高性能合金，该MSEA论文受到了广泛关注，已经被引用234次。 

 已经发表的相关论文如下：

[1] L.B. Chen, R. Wei, K. Tang, J. Zhang, F. Jiang*, L. He, J. Sun. Heavy carbon alloyed FCC-structured high entropy alloy with excellent combination of strength and ductility, Materials Science and Engineering A. 716 (2018) 150–156. （SCI应用234次）.

[2] L.B. Chen, R. Wei, K. Tang, J. Zhang, F. Jiang*, J. Sun. The ductile-brittle transition of carbon alloyed Fe₄₀Mn₄₀Co₁₀Cr₁₀ high entropy alloys. Materials Letters. 236 (2019) 416–419. （SCI应用67次）.

[3] K. Tang, L.B. Chen, S. Wang, R. Wei, Z.Y. Yang, F. Jiang*, J. Sun. Development of a large size FCC high-entropy alloy with excellent mechanical properties. Materials Science and Engineering A. 761(2019)138039. （SCI应用36次）.

[4] L.B. Chen, T.H. Cao, R. Wei**, K. Tang, C. Xin, F. Jiang*, J. Sun. Gradient structure design to strengthen carbon interstitial Fe40Mn40Co10Cr10 high entropy alloys. Materials Science and Engineering A.772 (2020) 138661. （SCI应用72次）.

[5] K. Tang, Y.K. Wu, R. Wei, L.B. Chen, S. Lu, Y.L. Qi, F. Jiang*, J. Sun. Achieving superior cryogenic tensile properties in a Ti-doped (Fe₄₀Mn₄₀Co₁₀Cr₁₀)_96.7C_3.3 high-entropy alloy by recovering deformation twinning. Materials Science and Engineering A. 808 (2021) 140927. （SCI引用35次）.

[6] Y. H. Shi, J.Q. Wang, P.F. Yun, K. Tang, L.B. Chen,* , R. Wei , J. Tian , Y.K. Wu, F.Jiang** . Achieving high performance low-cost Co-free FeMnCrNi-based medium entropy alloys via multiple synergistic strategies. Journal of Alloys and Compounds 1032 (2025) 181159.

 

[7] Y.H. Shi, L.B. Chen^*, T.H. Cao, R. Wei, Z.Y. Yang, Y.H. Li, C. Yang, X.X. Wan, Y.K. Wu, F. Jiang^**. Charpy impact behavior and fracture mechanisms in cost-effective ferrous medium-entropy alloy at ambient and cryogenic temperatures. Intermetallics 178 (2025) 108628.

 

[8] Y.H. Shi, Z.Y. Yang, L.B. Chen*, R. Wei, Y.K. Wu, F. Jiang*. Superior strength-ductility synergy in a cost-effective (Fe40Mn40Cr10Ni10)96.6C3Ti0.4 medium-entropy alloy processed by cryogenic rolling and low-temperature annealing. Journal of Alloys and Compounds 1050 (2026) 185507.