非平衡凝固理论的发展  

The development of non-equilibrium solidification theories

作　　者：王海丰[1] 王慷[1] 况望望 刘峰[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,西安710072

出　　处：《中国科学：技术科学》2015年第4期358-376,共19页Scientia Sinica(Technologica)

基　　金：国家杰出青年科学基金(批准号:51125002);国家重点基础研究发展计划(编号:2011CB610403);国家自然科学基金(批准号:51431008;51134011;51371149;51101122);西北工业大学基础研究基金(批准号:JC20120223);凝固技术国家重点实验室自主课题(编号:92-QZ-2014)资助项目

摘　　要：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 non-equilibrium solidification technology is developing very fast while the designing of solidification processes still relies on classical theories and empirical relations, which can no longer satisfy the increasing need for controlling of solidification conditions. The classical solidification theories are based on several major assumptions, such as linear liquidus/solidus, ideal solution, local equilibrium and they usually focus on model alloys instead of real industrial concentrated multi-component alloys. The discrepancies between classical theories and practical conditions demand us to abandon these classical assumptions so that the solidification theories can be applied to industrial processes. The current paper reviewed the recent development of non-equilibrium solidification theories for single-phase solid solution alloys. For dilute binary alloys, the microscopic interface kinetics, interface stability, dendrite growth and the micro-macro overall transformation kinetics were reviewed and the significances of nonlinear liquidus/solidus were illustrated. For concentrated binary and multi-component alloys the interface kinetics, interface stability and dendrite growth were reviewed with an emphasis on the importance of interaction between the components. The newly-developed non-equilibrium theories can give more accurate description of complicated solidification processes, thus promote the application of the solidification theories to industrial processes.

关 键 词：非平衡凝固 界面动力学 界面稳定性 枝晶生长 全转变动力学 

分 类 号：TG111.4[金属学及工艺—物理冶金]