Ag芯增强Bi-2212多芯线材的制备  

Fabrication of Bi-2212 Wires by Ag Core Strengthener

作　　者：郝清滨[1] 李成山[1] 张胜楠[1] 白利锋[1] 马晓波[1] 张平祥[1] 

机构地区：[1]西北有色金属研究院超导材料研究所,陕西西安710016

出　　处：《稀有金属》2012年第6期898-903,共6页Chinese Journal of Rare Metals

基　　金：国家科技部973项目(2011CBA00104);国际科技合作计划项目(S2010GR0518);国家自然科学基金项目(51102198)资助

摘　　要：为解决Bi-2212线材冷加工过程中的断芯问题,采用中间银丝增强的19×18+1芯的导体结构代替常规的85×7芯的结构,并研究关键热处理参数熔化温度对线材微观结构及载流性能的影响,同时对微观结构的形成机制进行了解释。研究发现,采用中间银丝加强的19×18+1芯结构,可有效防止线材的断芯,显著改善了线材的加工均匀性,线材的载流性能增加了40%。熔化温度对线材载流性能影响较大,温度过高或过低都会导致线材中出现大量尺寸与芯丝尺寸相当的(Sr,Ca)xCuyOδ(AEC相),严重阻碍电流的流通。合适的熔化温度烧结的线材中AEC相较少且尺寸较小,另外还存在较多芯丝间的桥连,增加了电流的输运通道,改善了线材的载流性能。Because there were several hundred cores in a single Bi-2212 wire, the phenomena of core wire breaking occurred commonly during drawing. The Bi-2212 wire with 19 × 18 ＋ 1 filament configuration by Ag core wire strengthener was fabricated instead of common filament configuration of 85 × 7 to avoid the core wire breaking. Meanwhile, the effects of melting temperature on the microscopic morphology and the current carrying capacity of Bi-2212 wire were studied. And the formation mechanism of the microscopic morphology was also investigated. The results showed it was effective to avoid the core wire breaking of Bi-2212 using the 19 × 18 ＋ 1 filament configuration by Ag core wire strengthener, the uniformity of distortion during the drawing was improved, and the critical cur- rent increased 40% than that of traditional wire. The mehing temperature had a significant effect on the critical current. If the melting temperature was too high or too low, lots of AEC precipitates with the size as large as the ceramic core appeared in Bi-2212 wire, which deteriorated the critical current of Bi-2212 wire significantly. If the melting temperature was suitable, there would be small amount of AEC phase in the wire and the size of that was smaller. Moreover, there would be lots of bridging between core and core, which provid- ed route way for current. So the critical current of Bi-2212 wire was improved.

关 键 词：BI系超导体 导体结构 熔化温度 

分 类 号：TH142.8[一般工业技术—材料科学与工程]