摘要
细晶制造一般指通过各种制造技术与工艺将构件中粗大的宏微结构进行细化,促进细晶组织、化学成分、物理性质和加工性能的空间分布均匀性,减小构件局部形性协同离散超差,提升金属构件整体服役性能。典型粗大组织包括柱状晶、树枝晶、金属间化合物和网状共晶等。细晶制造具有重要科学和工程意义,广泛应用于航空航天、轨道交通、汽车行业、海洋船舶和基础建设等领域,其关键技术是实现金属细晶结构调控工程化。细晶结构调控工程化的主要方法有细晶凝固和固态变形,前者为重点论述内容。在细晶结构调控工程化的机理/理论或高效细化剂方面,研究工作取得了诸多进展。通过Al和Mg金属及合金的铸造实验,众多学者发现凝固细晶调控主要取决于形核颗粒和偏析元素。事实上,细晶凝固研究已涵盖到了Al、Mg、Fe、Ti、Cu、Sn、Zn和中/高熵合金等金属构件,细晶结构尺寸可调控范围包括:非晶—纳米晶—亚微米晶—微米晶—亚毫米晶—毫米晶—厘米晶—大单晶。但是,适用于所有金属细晶凝固的共性科学机理/理论尚未完全形成共识。并且,基于现有理论所开发的新型晶粒细化剂效率并不一定都高,这表明当前理论可能忽略了其它未发现的调控因素。基于70多年来细晶凝固领域科学发展,总结了金属凝固细晶调控的共性科学基础与工程实践研究,阐明了当前主流的铸造金属细晶调控理论的异同,揭示了细晶铸造所需细化剂的本征物化条件,简述了固态形变细晶与缺陷工程化,最后探索了细晶制造在航空航天环形构件研发中的工程化应用。
The fine-grained manufacturing defines the refinement of coarsening macro-and micro-structures of the components by various manufacturing technologies and processes. It facilitates to promote the homogeneity of spatial distribution of fine-grained structures,chemical compositions,physical properties and machinability in the components,reduce the local discrete error tolerance of geometric shape and mechanical properties,and improve the overall service performance of metallic components. The representative coarsening structures include columnar grains,dendrite grains,intermetallic compounds,eutectic networks,and etc. Due to its scientific and engineering significance,the fine-grained manufacturing is widely applied in the aerospace,railway transportation,automotive,marine vessels,and construction industries,where the key technology is to realize the engineering of fine-grained structures regulation and control. The engineering of fine-grained structures regulation and control is usually implemented in two methods i. e. the fine-grained solidification and the solid deformation. The former method is the focus. Extensive advances are obtained for theoretical investigation and high efficient refiners.Based on the casting experiments of Al and Mg alloys,the grain refinement of solidification is found to mainly depend on the nucleant particles and segregating solutes. Actually,work in the fine-grained solidification has spanned from the Al,Mg,Fe,Ti,Cu,Sn,Zn to the medium-/high-entropy alloys,with controllable sizes of fine-grained structures spanning from amorphous-nanocrystalline-submicron crystal-micron crystal-submillimeter crystal-millimeter crystal-centimeter crystal-large single crystal. However,there is still no full consensus on the general principles for all cast metals. Meanwhile,some grain refiners predicted do not necessarily deliver high efficiency,which probably implies that the current theories may ignore other unknown regulating and controlling factors. Based on the development of finegrained solidificat
作者
刘峙麟
LIU Zhi-lin(State Key Laboratory of High Performance and Complex Manufacturing,Central South University,Changsha 410083,China;Light Alloy Research Institute,Central South University,Changsha 410083,China;College of Mechanical and Electrical Engineering,Central South University,Changsha 410083,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2021年第5期1-16,共16页
Journal of Plasticity Engineering
基金
国家自然科学基金资助项目(51975592)。
关键词
金属构件
细晶制造
调控机理
工程应用
metallic components
fine-grained manufacturing
controlling mechanisms
engineering application
