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近年来,非平衡凝固技术迅速发展,但相应的工艺设计仍主要依赖于经验或半定量理论,无法满足当前材料加工过程控制的苛刻要求.经典凝固理论的建立基于诸多假设,如相图的线性液/固相线假设、合金热力学性质的理想稀溶液假设及体系动力学过程的局域平衡假设,其研究对象为模型合金而非实际浓溶液、多元合金等;经典与现实的差距迫切需要突破经典假设的束缚以更好地发挥凝固理论在工艺设计中的指导作用.本文针对单相固溶体合金,介绍了近年来松弛经典假设后凝固理论的发展.阐述了基于理想稀溶液假设的二元合金微观尺度界面动力学、界面稳定性、枝晶生长,以及耦合微观与宏观的全转变动力学理论的发展,阐明了非线性液/固相线的重要作用.针对二元、多元浓溶液合金,介绍了界面动力学、界面稳定性和枝晶生长理论的发展,阐述了组元间互作用的重要性.当前凝固理论发展摒弃了诸多经典假设,缩短了理论研究与实际工业生产的差距,拓宽了凝固理论的应用范围,更准确地描述了非平衡凝固过程,促进了非平衡凝固理论在工业生产中的应用.
In recent years, the rapid development of non-equilibrium solidification technology, but the corresponding process design is still mainly rely on empirical or semi-quantitative theory, can not meet the current material control requirements of the harsh process.The establishment of classical solidification theory based on many assumptions, such as the linear phase diagram Liquid / solid phase assumption, ideal dilute solution assumptions of the thermodynamic properties of the alloy and the local equilibrium assumption of the kinetic process of the system, the research objects are model alloys rather than actual concentrated solutions, multivariate alloys, etc .; the gap between classic and reality urgently needs breakthrough Classical assumptions in order to better play the role of solidification theory in the process of design guidance.In this paper, single-phase solid solution alloys, introduced in recent years after the relaxation of the classical hypothesis solidification theory development is described based on the ideal dilute solution binary alloy The development of dynamics theory of micro-scale interface dynamics, interfacial stability, dendritic growth, and the coupling micro and macro all-transformation kinetics has been discussed, and the important role of nonlinear liquid / solid phase lines has been clarified. The development of interfacial dynamics, interfacial stability and dendritic growth theory are introduced, and the interaction between the components The development of solidification theory abandoned many classic hypotheses, shortened the gap between theoretical research and actual industrial production, widened the scope of application of solidification theory, described the non-equilibrium solidification process more accurately and promoted the theory of non-equilibrium solidification in the industrial Application in production.