YBCO带材无阻连接热退火效应研究  

Study on Heat Treatment Effect of YBCO Tape in Superconducting Welding

作　　者：储梦梅 赵苏串[1] 陈静 刘志勇[1,2] 周洪斌 白传易 周迪帆[1] 李敏娟[1] 蔡传兵 CHU Mengmei;ZHAO Suchuan;CHEN Jing;LIU Zhiyong;ZHOU Hongbin;BAI Chuanyi;ZHOU Difan;LI Minjuan;CAI Chuanbing(Shanghai Key Laboratory of High Temperature Superconductors,Physics Department,Shanghai University,Shanghai 200444,China;Shanghai Creative Superconductor Technologies Co.Ltd.,Shanghai 201401,China)

机构地区：[1]上海大学理学院物理系,上海市高温超导重点实验室,上海200444 [2]上海上创超导科技有限公司,上海201401

出　　处：《低温物理学报》2020年第1期25-31,共7页Low Temperature Physical Letters

基　　金：国家重点研发计划(2016YFF0101701);装备部制造领域基金项目(6140923050202);中国科学院先导项目(XDB25020200);上海市科学技术委员会(16521108400,16DZ0504300,14521102800);国家自然科学基金(51572165,11174193)资助的课题.

摘　　要：超导焊接是第二代高温超导(2G-HTS)带材研究的重要内容,在两根超导带材中间生长超导连接层可实现无阻连接.在超导连接层的生长过程中,原来的两根超导带材需再次经历热处理,目前这方面的研究甚少.本文系统研究了780℃热退火中,时间、气氛对带材性能的影响.分析了样品的显微结构、表面形貌以及临界电流密度(J c),结果表明:2 h干氮氧气氛有利于提高原始带材的性能;湿氮氧气氛使J c值降低.这可能是湿气的存在增加了晶粒缺陷,使杂质的扩散通道增加,从而Ba-Cu-O积聚生长,造成YBCO性能恶化.在文中我们还利用XRD进行了应力拟合分析了应力变化.Realization of non-resistive,superconducting welding is of great significance for the application of second generation high-temperature superconducting(2G-HTS)tapes.Superconducting welding requires generally a superconducting joint made between two well processed HTS tapes.And these two HTS strips need to undergo the heat treatment again to induce the texture growth of the joint layer.There is yet little work focusing on the effects of repeated heat treatment on the HTS tapes.In this paper,we systematically studied the effects of re-heat time and atmosphere at 780℃on the properties of HTS strips.The microstructure,surface morphology,and critical current density(Jc)of the sample were characterized.The results showed that re-heating in mixed dry nitrogen and oxygen atmosphere for2 hours improved the performance of the original strip,however,wet nitrogen and oxygen atmosphere decreased the Jc value.This is considered due to the presence of moisture that increases grain defects and diffusion channels for impurities,and thus accumulates Ba-Cu-O,which deteriorates YBCO performance.The stress changes during the process were as well analyzed using stress fitting based on XRD results.

关 键 词：YBCO 带材 无阻连接 热退火 

分 类 号：TM26[一般工业技术—材料科学与工程]