强磁场下合金熔体中原子扩散系数测量研究进展  

Research Progress in Measurement of Atomic Diffusivity in Alloy Melts under High Magnetic Field

作　　者：林文浩 蔡浩[1,2] 刘颖 周邦飞[1,2] 郑天祥 钟云波[1] LIN Wenhao;CAI Hao;LIU Ying;ZHOU Bangfei;ZHENG Tianxiang;ZHONG Yunbo(State Key Laboratory of Advanced Special Steels,Shanghai University,Shanghai 200444,China;School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学省部共建高品质特殊钢冶金与制备国家重点实验室,上海200444 [2]上海大学材料科学与工程学院,上海200444

出　　处：《铸造技术》2022年第8期654-663,I0030,共11页Foundry Technology

基　　金：国家自然科学基金(U1732276);国家重点研发计划(2016YFB0301401);上海市科委面上项目(15520711000);省部共建高品质特殊钢冶金与制备国家重点实验室、上海市钢铁冶金新技术开发应用重点实验室自主课题(SKLASS2021-Z06);中国科协青年人才托举计划;长江学者奖励计划。

摘　　要：合金熔体扩散系数的准确测量有助于了解金属熔体的原子结构和原子迁移的物理本质,为液态金属原子扩散机制和物理模型建立以及后续的材料设计等诸多研究提供实验依据。由于合金熔体中不可避免存在多种类型流动,准确测量合金熔体中扩散系数仍然存在挑战。本文综述了合金熔体扩散系数的几种测量技术,包括长毛细管技术、毛细管-熔池技术、剪切单元技术、滑动剪切技术、X射线成像技术和重力辅助自动对接技术,分析了在地面、微重力以及强静磁场等测量环境下利用上述技术对扩散系数的测量,对比分析了目前测量技术的优缺点。通过重力辅助自动对接装置,实现了高达22 T强静磁场环境下扩散系数的测量。强静磁场能够有效抑制熔体对流,并获得与微重力场下所测数据相当的扩散系数值。利用强静磁场的磁流体动力学效应有望创造纯扩散的测量环境,进一步提高扩散系数测量的准确性。The accurate measurement of the diffusion coefficient of alloy melt is helpful to understand the atomic structure of metal melt and the physical nature of atomic migration,which provides experimental basis for the research of atomic diffusion mechanism and physical model establishment of liquid metal and subsequent material design.Accurate measurement of diffusivity in alloy melts remains a challenge due to the inevitable presence of multiple types of flows.In this paper,several measurement techniques for diffusivity of alloy melt are reviewed,including long capillary tube technique,capillary-molten pool technique,shear element technique,sliding shear technique,X-ray imaging technique and gravity assisted automatic docking technique.The measurement of diffusion coefficient using the above technology in the ground was analyzed,microgravity and strong static magnetic field,and compares the advantages and disadvantages of the current measurement technology.By means of gravity assisted automatic docking device,the diffusion coefficient of up to22 T strong static magnetic field is measured.The strong static magnetic field can effectively suppress the melt convection,and the diffusivity values are comparable to those measured in microgravity field.It is possible to use the MHD effect of strong static magnetic field to create a pure diffusion measurement environment and further improve the accuracy of diffusion coefficient measurement.

关 键 词：合金熔体 扩散系数 熔体对流 强静磁场 

分 类 号：TG111.6[金属学及工艺—物理冶金]