深过冷多元Fe基高阻尼合金的相选择和组织性能调控机理

本项目面向航空航天和国防军工领域对阻尼金属材料的重大需求，以二元Fe-Mn和Fe-Cr合金为基础，增加相关溶质元素形成三~五元Fe-Mn/Cr-X-Y-Z合金，基于混合熵理论开展合金的成分设计，采用从头算分子动力学预测合金成分－结构－性能的相关规律，提出高性能Fe基阻尼合金的优化设计理论。采用电磁悬浮技术，辅以静电悬浮和自由落体实验方法，对Fe基阻尼合金的快速凝固机理进行系统研究，重点探索深过冷条件下合金的相选择规律和微观结构特征，深入分析快速凝固过程中马氏体相优先形核机理和晶体生长动力学，探索非平衡凝固过程与固态相变的相关性，研究合金阻尼性能随振动频率、温度和振幅的变化规律。确定“合金成分－凝固参数－相选择－组织形态－结构缺陷－阻尼性能”的定量化关系，为高性能Fe基阻尼合金的优化设计和先进制备提供理论依据，发展一种以深过冷快速凝固为特征的高性能Fe基阻尼合金的超常制备技术。

This project aims for the significant demand of high damping metallic materials in aerospace and defense military fields. The Fe-Mn/Cr-X-Y-Z alloys are selected based on the binary Fe-Mn and Fe-Cr alloys with additions of different solute elements. The high-entropy alloy theory is applied to design high performance alloys, and the ab-initio Molecular Dynamics is used to predict the relationship between alloy composition, structure and properties. Electromagnetic levitation, electrostatic levitation and drop tube techniques are carried out to investigate the rapid solidification mechanism of Fe-based damping alloys. The phase selection and structure characteristics during rapid solidification are focused to clarify the nucleation mechanism and growth kinetics of martensitic phases. The relationship between non-equilibrium solidification and solid phase transformation is explored based on the investigation of damping property, solidification parameters and microstructures. The quantitative relations between alloy composition, solidification parameters, phase selection, microstructure defects and damping performance are determined. It provides a theoretical basis for the optimized design method and advanced preparation approach of damping alloy with high performance. The development of extraordinary solidification technology characterized by high undercooling and rapid solidification opens a promising way for the preparation of high-performance Fe-based damping alloys.