定向凝固晶粒竞争生长的研究进展  

Recent Progresses in Competitive Grain Growth During Directional Solidification

作　　者：王锦程[1] 郭春文[1] 李俊杰[1] 王志军[1] WANG Jincheng;GUO Chunwen;LI Junjie;WANG Zhijun(State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi＇an 710072, China)

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：《金属学报》2018年第5期657-668,共12页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目Nos.51371151和51571165~~

摘　　要：竞争生长是材料微观组织演化过程中普遍存在的现象,不同组织间(包括相、枝晶、晶粒等)均可能存在竞争生长,这些竞争作用对最终微观组织的形成及力学性能具有重要影响。不同取向晶粒间的竞争生长控制是材料微观组织调控的重要环节,尤其是对定向单晶叶片的制备,不同取向晶粒间的竞争生长是决定能否成功获得完整单晶结构的关键因素。近年来,一方面单晶材料制备要求的不断提高,迫切需要有关晶粒竞争生长机制及规律方面的理论性指导,另一方面经典晶粒竞争生长理论预测结果与实验观测并不相符,有时甚至可能完全相反,这使得定向凝固过程中不同取向晶粒间的竞争生长问题日益成为一个热门的研究课题。本文首先回顾了Walton-Chalmers模型的晶粒竞争生长机制及其所受到的严重挑战,然后分别对定向凝固二维条件下汇聚生长和发散生长及三维条件下晶粒竞争生长的研究现状进行了述评,并介绍了本课题组近年来基于相场法数值模拟在定向凝固晶粒竞争生长研究方面的工作进展,最后对定向凝固过程中不同取向晶粒之间的竞争生长研究进行了总结与展望。Competitive growth between different structures including phases, dendrites and grains is a common phenomenon existing in various microstructure evolution processes. The overgrowth outcome of competitive growth has a paramount influence on final solidification microstructures and mechanical behaviors of materials. The competitive grain growth during directional solidification is a key factor for microstructures controlling, especially for the preparation of single crystal turbine blades. In recent years, the competitive grain growth during directional solidification becomes a hot spot due to an increasing demand for the single crystal preparation and inconsistent experimental results with the classical WaltonChalmers model. In this paper, the mechanism of competitive grain growth based on the classical WaltonChalmers model and its challenges were firstly discussed, and then some recent research progresses in converging growth and diverging growth in two dimensional spaces, and non-uniplanar growth in three dimensional spaces were reviewed. Furthermore, the recent works of our group on competitive grain growth during directional solidification by using the phase field method were introduced. Finally, the outlooks of future studies on competitive grain growth during directional solidification are presented.

关 键 词：定向凝固 晶粒竞争生长 相场法 研究进展 

分 类 号：TG244[金属学及工艺—铸造]