Microstructure and Mechanical Properties of Face‐Centered‐Cubic‐Based Cr‐Free Equiatomic High‐Entropy Alloys
Microstructure and Mechanical Properties of Face‐Centered‐Cubic‐Based Cr‐Free Equiatomic High‐Entropy Alloys
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DOI：
10.1002/adem.202000848
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发表时间：
2020-11
影响因子：
3.6
通讯作者：
Xinwang Liu;Peng Liu;Weibin Zhang;Q. Hu;Qiang Chen;N. Gao;Zeli Tu;Z. Fan;Gang Liu
中科院分区：
文献类型：
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作者：
Xinwang Liu;Peng Liu;Weibin Zhang;Q. Hu;Qiang Chen;N. Gao;Zeli Tu;Z. Fan;Gang Liu
具有面心立方（FCC）结构的高熵合金（HEAs），例如，典型的CrMnFeCoNiHEA具有沉淀脆性σ相的强烈倾向，因为Cr是强σ稳定剂。为了开发具有减轻的σ相的担忧的HEA，在Cr-Mn-Fe-Co-Ni HEA系统中用Cu代替Cr以形成Mn-Fe-Co-Ni-Cu系统。五元合金及其四元子集均在铸态下进行研究。研究了合金的组织演变、相组成和室温拉伸性能。HEAs具有多相FCC结构，晶格常数略有不同，并且在大多数系统中观察到球形富Cu颗粒。所有合金均表现出枝晶状形态，由于溶质分配，在枝晶间区域存在Cu偏析。所研究的HEAs显示出良好的强度、大的延伸率和加工硬化能力。强度归因于组合机制，特别是富Cu颗粒的沉淀强化。研究结果提供了一些模型HEA系统，以进一步有效地指导广泛组成空间的无铬HEA的设计。
High‐entropy alloys (HEAs) with face‐centered‐cubic (FCC) structures, e.g., the typical CrMnFeCoNi HEA, have a strong tendency to precipitate brittle sigma phases, as Cr is a strong sigma stabilizer. To develop HEAs with alleviated concerns of sigma phases, Cu for Cr in the Cr‐Mn‐Fe‐Co‐Ni HEA system is substituted to form a Mn‐Fe‐Co‐Ni‐Cu system. The quinary alloy and its quaternary subsets are investigated all in as‐cast state. Microstructure evolution, phase constituent, and tensile properties at room temperature are studied. The HEAs have multi‐phase FCC structures with slightly different lattice constants and spherical Cu‐rich particles are observed in most systems. All alloys exhibit dendrite‐like morphology with Cu segregation in interdendritic regions due to the solute partitioning. The investigated HEAs show good strengths, large elongations, and work hardening capability. The strengths are attributed to combined mechanisms, especially the precipitation strengthening by Cu‐rich particles. The findings provide some model HEA systems for further usefully guiding design in the widely compositional space of Cr‐free HEAs.