Based on the hypothesis of lattice distortion, compositional complexity of high entropy alloys (HEAs) induces severe lattice distortion. Recent studies on the experimental and theoretical approaches to lattice distortion have been made to evaluate this hypothesis. However, the understanding of this effect is not complete due to their highly complex compositions and limited direct evidence. This work was designed to systematically study the effect of compositional complexity from unary to quinary compositions (Ni, FeNi, FeNiCo, FeNiCoCr and FeNiCoCrMn). To focus on the effect of interactions between constituent elements, the microstructural effect was minimized by controlling similar microstructural features such as grain size and residual strain. The micro lattice strain was evaluated on X-ray line profile analysis using the Williamson-Hall method and the local lattice strain was assessed by using pair distribution function (PDF) method through the total scattering data using the synchrotron X-ray diffraction measurement. Analysis on both the micro and local scales indicates that severe lattice distortion is not evident in FeNiCoCrMn HEA. Lattice strain and solid solution hardening are comparable between FeNiCoCrMn HEA and its sub-alloys. The high compositional complexity of FeNiCoCrMn HEA does not lead to a strong effect on lattice strain and solid solution hardening.

基于晶格畸变的假设，高熵合金 (HEAs) 的成分复杂性会导致严重的晶格畸变。最近对晶格畸变的实验和理论方法进行了研究，以评估这一假设。然而，由于其高度复杂的成分和有限的直接证据，对这种效应的理解并不完整。这项工作旨在系统地研究从一元到五元成分（Ni、FeNi、FeNiCo、FeNiCoCr 和 FeNiCoCrMn）的成分复杂性的影响。为了关注组成元素之间相互作用的影响，通过控制类似的微观结构特征（例如晶粒尺寸和残余应变）来最小化微观结构影响。使用威廉姆森-霍尔方法在 X 射线线轮廓分析上评估微晶格应变，并通过使用同步加速器 X 射线衍射测量的总散射数据使用对分布函数 (PDF) 方法评估局部晶格应变。微观和局部尺度的分析表明，FeNiCoCrMn HEA 中没有明显的严重晶格畸变。FeNiCoCrMn HEA 及其子合金的晶格应变和固溶硬化相当。FeNiCoCrMn HEA 的高成分复杂性不会对晶格应变和固溶硬化产生强烈影响。微观和局部尺度的分析表明，FeNiCoCrMn HEA 中不存在严重的晶格畸变。FeNiCoCrMn HEA 及其子合金的晶格应变和固溶硬化相当。FeNiCoCrMn HEA 的高成分复杂性不会对晶格应变和固溶硬化产生强烈影响。微观和局部尺度的分析表明，FeNiCoCrMn HEA 中不存在严重的晶格畸变。FeNiCoCrMn HEA 及其子合金的晶格应变和固溶硬化相当。FeNiCoCrMn HEA 的高成分复杂性不会对晶格应变和固溶硬化产生强烈影响。