摘要
金属熔体微观上是不均匀的,其独特的结构在后续凝固过程中会显著影响材料的微观组织,决定产品的最终性能。研究金属熔体结构及其外场作用下的转变对凝固科学与技术的发展具有重要指导意义。金属熔体中存在不同类型的短程有序团簇,在外界条件下,原子团簇会发生消解、重排等构型变化,即发生熔体结构转变。熔体结构转变广泛存在于金属与合金中。系统认识熔体结构转变的物理本质,进而通过外场有效调控熔体结构转变,改善凝固组织,优化合金综合性能的方法极具前景。本文介绍了金属熔体结构及其转变的概念和相关理论模型,综述了其对凝固行为和性能调控方面的研究现状。并围绕调控熔体转变过程这一科学问题,详细介绍了在压力、温度等外场下金属熔体结构转变的研究进展,并提出强磁场在金属熔体结构转变过程中的重要影响,以及多场耦合下金属熔体结构研究的发展方向。
The structure of metal melt is heterogeneous, having a significant effect on the microstructure and phase morphologies in the subsequent solidification process and consequently determining the final performance of the product.The study of the metal melt structure and the transition with external fields also shows the great guidance on developing the solidification science and technology. There exists large quantities of atomic clusters within metal melts. Under external conditions, the clusters will undergo configurational changes such as dissipation and rearrangement, i.e., liquid-liquid structure transition(L-LST) that has been found in many metals and alloys. Getting more knowledge of the physical nature of L-LST systematically, further regulating the L-LST process under the external field, is a promising method to optimize the microstructures and properties of alloys. In this work, the concepts and theoretical models of metal melt structure and its transformation are reviewed generally, followed by the research progress on the L-LST-controlled solidification behavior and properties. Subsequently, the effect of the external fields such as temperature and pressure on the metal melt structure transition is introduced in detail, and the critical roles of strong magnetic field are proposed and emphasized for the first time. The development for research direction of metal melt structure considering multi-field coupling effect is also put forward.
作者
刘浩翔
边张驰
卜凡
贺一轩
王军
李金山
LIU Haoxiang;BIAN Zhangchi;BU Fan;HE Yixuan;WANG Jun;LI Jinshan(State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi'an 710072,China;Center of Advanced Lubrication and Seal Materials,Northwestern Polytechnical University,Xi'an 710072,China)
出处
《铸造技术》
CAS
2022年第9期733-754,I0026,共23页
Foundry Technology
基金
国家自然科学基金(52104386,52127807)
凝固技术国家重点实验室自主课题(2022-TS-08)。
关键词
熔体结构转变
凝固行为
温度场
磁场
liquid-liquid structure transition
solidification behavior
temperature field
magnetic field
