多元Fe基合金的快速枝晶生长及其相场模拟研究

By glass fluxing technique and phase-field simulation method, the nonequilibrium rapid solidification of Fe-Ni-Cu-X-Y [X,Y:(Ti,Cr,Si)] alloys will be investigated. Undercooling of (0.1-0.2)TL for multicomponent Fe-based alloys will be obtained, the ability of undercooling and the internal nucleation features will be discussed. The three-dimensional rapid solidification of the alloys will be realized, the mechanism of rapid dendrite growth, the microstructure evolution of the subsequent phase transformation will be studied, the solute trapping effect and the mechanism of micro-segregation in multicomponent system will also be discussed. Based on the phase-field simulation method, the temperature and solute distribution in the undercooled multicomponent Fe-based alloy melt will be researched, and the rapid dendrite growth of the alloys will be simulated and dynamically displayed, also the influence of undercooling, interface characteristics and multi-field coupling parameters on the morphology of the dendrite growth will be explored. The relationship between the physical properties of the rapidly solidified alloys and microstructure will be experimentally studied. On the basis of experimental research and theoretical analysis, the rapid solidification theory of multicomponent Fe-based alloys will be established and developed, also the research foundation for the development of new multicomponent alloy materials will be provided.

采用大体积合金熔体深过冷实验技术和相场理论模拟方法，研究Fe-Ni-Cu-X-Y [X,Y:(Ti, Cr, Si)] 多元Fe基合金的非平衡快速凝固过程。在熔体浸浮条件下使多元Fe基合金获得（0.1-0.2）TL的过冷度，探究深过冷合金熔体的过冷能力和内部形核特征。实现深过冷多元Fe基合金熔体的三维快速凝固，研究非平衡快速枝晶生长动力学机制，以及后续凝固过程中的复杂相变机理与组织演化规律，揭示多元溶质截留效应和微观偏析形成机制。基于相场理论计算，研究快速凝固过程中多元Fe基合金熔体的温度场和溶质场分布特征。对多元Fe基合金的快速枝晶生长过程进行动态模拟再现，探索过冷度、界面特性以及多场耦合参数对枝晶生长形貌的影响规律。实验测定快速凝固多元Fe基合金的物理性能与微观组织的本征关系。在实验研究和理论分析的基础上，发展和完善多元Fe基合金快速凝固理论，并为研制新型多元合金材料提供研究基础。