模具角度对核聚变用Bi-2212线材加工的影响  

Influence of Die Angle on Bi-2212 Wire Processing for Nuclear Fusion

作　　者：焦高峰[1] 郝清滨[1] 徐晓燕[1] 刘国庆[1] 刘学谦 贾佳林[1] 张胜楠[1] JIAO Gaofeng;HAO Qingbin;XU Xiaoyan;LIU Guoqing;LIU Xueqian;JIA Jialin;ZHANG Shengnan(Northwest Institute for Nonferrous Metal Research,Xi’an 710016,Shaanxi Province,China)

机构地区：[1]西北有色金属研究院,陕西省西安市710016

出　　处：《发电技术》2024年第6期1067-1073,共7页Power Generation Technology

基　　金：国家重点研发计划项目(2021YFB3800201);国家自然科学基金项目(52277029)。

摘　　要：【目的】随着稳态强磁场的快速发展,对超导磁体的性能及均匀性要求越来越严苛,导致目前生产的Bi_(2)Sr_(2)CaCu_(2)O_(x)(Bi-2212)高温超导线材的综合性能无法满足应用要求。为提升Bi-2212线材的性能及均匀性,实现综合性能更优异的超导线材制备,多芯线材的均匀加工技术至关重要。模具角度(简称“模角”)是线材的重要参数,为此,研究了不同模角对线材加工的影响。【方法】采用粉末装管法制备了多根Bi-2212线材,并使用半模角分别为3°、7°和14°的合金拉丝模具对这些线材进行加工。在实验过程中,对线材的微观结构、粉末硬度及超导物理性能进行了系统研究。【结果】采用较小模角加工的线材表现出更高的载流性能,特别是半模角为3°的样品,其载流性能是半模角为14°样品的1.56倍。大模角加工的线材出现芯丝断裂和银层破裂现象,导致性能下降,而小模角线材则能保持结构完整性。此外,模角的选择对线材的Ag/超导材料界面光滑度有显著影响,小模角线材的界面光滑度更优,进一步影响了超导芯丝的织构和线材的载流性能。【结论】较小的半模角有助于保持多芯Bi-2212线材芯丝的结构完整性,并通过改善织构来提高线材的载流性能。研究结果为制备高性能Bi-2212线材提供了工艺指导。[Objectives]With the rapid development of the steady high magnetic field,the requirements for the performance and uniformity of superconducting magnets have become increasingly stringent,resulting in the current Bi_(2)Sr_(2)CaCu_(2)O_(x)(Bi-2212)high-temperature superconducting wires failing to meet the application requirements in terms of comprehensive performance.In order to enhance the performance and uniformity of Bi-2212 superconducting wires and achieve the preparation of wires with superior comprehensive performance,the uniform processing technology for multi-core wires is of utmost importance.Die angle is an important parameter of the wire.Therefore,the influence of different die angles on the wire processing was studied.[Methods]Multiple Bi-2212 wires were prepared using the powder-in-tube method and processed with alloy drawing dies with half die angles of 3°,7°and 14°,respectively.During the experiment,systematic investigations were conducted on the microstructure,powder hardness,and superconducting physical properties of the wires.[Results]The wires processed with smaller die angles show higher current-carrying capabilities,especially,the current-carrying capacity of the sample with a 3°half die angle is 1.56 times that of the sample with a 14°half die angle.The Wires processed with a large die angle show core wire fractures and silver layer ruptures,leading to decreased performance,while the wires with smaller die angles maintain structural integrity.Furthermore,the choice of die angle significantly affects the smoothness of the Ag/superconductor interface,with wires processed at smaller die angles demonstrating superior interface smoothness.This further influences the texture of the superconducting filaments and the current-carrying capacity of the wires.[Conclusions]Smaller half die angles help maintain the structural integrity of the multi-filament Bi-2212 wire cores and improve the current-carrying capacity by enhancing the texture.The research results provide process guidance for the prepar

关 键 词：核聚变 稳态强磁场 高温超导材料 超导磁体 粉末装管法 Bi-2212线材 模角 载流性能 

分 类 号：TK01[动力工程及工程热物理] TM26[一般工业技术—材料科学与工程]