强磁场对丁二腈枝晶生长速度及特征尺寸的影响  

Effects of High Magnetic Field on the Growth Rate and Characteristic Size of Succinonitrile Dendrites

作　　者：陈梓健 李杰 闫育洁 李超[1,2] 张平祥 王军[1] CHEN Zijian;LI Jie;YAN Yujie;LI Chao;ZHANG Pingxiang;WANG Jun(State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi'an 710072,China;Xi'an Superconducting Magnet Technology Co.,Ltd.,Xi'an 710018,China;Northwest Institute for Nonferrous Metal Research,Xi'an 710016,China)

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072 [2]西安聚能超导磁体科技有限公司,陕西西安710018 [3]西北有色金属研究院,陕西西安710016

出　　处：《铸造技术》2022年第9期817-822,I0026,共7页Foundry Technology

基　　金：国家自然科学基金(52174375);凝固技术国家重点实验室自主课题(2021-TS-01)。

摘　　要：本文以透明类金属有机物丁二腈(SCN)为研究对象,采用原位观察方法研究了有无强磁场时丁二腈定向凝固组织形貌的变化。实验过程中,利用自行搭建的原位观察定向凝固装置分别在0、3 T磁场下对丁二腈进行定向凝固,并设置了3个温度梯度(5、10、15 K/mm),用光学显微镜记录了丁二腈的定向凝固过程,揭示强磁场对丁二腈定向凝固过程的影响机制。实验结果表明,无磁场下丁二腈的枝晶生长形态均为斜枝晶,随着温度梯度的升高,枝晶生长方向与温度梯度方向的夹角减小,生长速度加快,枝晶尖端半径减小,一、二次枝晶间距减小;施加了3 T磁场后发现,同一温度梯度下的枝晶形态由斜枝晶转变为胞状晶,枝晶生长方向与温度梯度方向的夹角增大,生长速度降低,枝晶尖端半径增大,同时一、二次枝晶间距增加。The transparent metalloid organic compound succinonitrile(SCN) was used as the research object in this paper,and the changes of microstructure of SCN during directional solidification with or without high magnetic field were studied by in-situ observation. During the experiment, the self-made in-situ observation directional solidification device was used to conduct directional solidification of SCN with 0 and 3 T magnetic field, and three temperature gradients(5, 10, 15 K/mm) were set. The process of directional solidification was photographed and recorded with an optical microscope, revealing the influence mechanism of high magnetic field on the directional process of SCN. The results show that the dendrite morphology of SCN is oblique dendrite without magnetic field. With the increase of temperature gradient, the growth rate of dendrites increases, the dendrite tile angle decreases, the dendrite tip radius decreases, and the primary and secondary dendrite arm spacing decreases;after applying 3 T magnetic field, it is found that the dendrite-to-cell transition occurs under the same temperature gradient, the growth rate of dendrites slows down, the dendrite tile angle increases, the dendrite tip radius increases, and the primary and secondary dendrite spacing increases.

关 键 词：强磁场 丁二腈 定向凝固 枝晶生长速度 特征尺寸 

分 类 号：TG249[金属学及工艺—铸造] TF19[冶金工程—冶金物理化学]