烧结温度对MgB_2超导线材微观结构及超导电性的影响  

Effects of Sintering Temperature on Microstructure and Superconductivity of MgB_2 Wires

作　　者：单迪[1,2] 刘国庆[2] 闫果[2] 周廉[2] 

机构地区：[1]西北工业大学,陕西西安710072 [2]西北有色金属研究院,陕西西安710016

出　　处：《热加工工艺》2010年第14期18-20,共3页Hot Working Technology

基　　金：国家自然科学基金资助项目(50877067)

摘　　要：使用干燥的B粉和Mg粉,采用分步反应法制备了SiC(40～45 nm)掺杂的MgB2/Nb/Cu超导线材。通过X射线衍射仪、扫描电子显微镜,研究了不同烧结温度对所制备样品的相组成、微观结构的影响。采用标准四引线法测定了样品的电阻温度曲线。结果表明:热处理温度对线材的微观结构有显著影响,适宜的热处理温度可提高C原子实际进入晶格取代B原子的数量。在750℃×2 h,C原子替代B的取代分数达3.73%。分步反应法制备MgB2超导线材可有效地引入B位C掺杂,从而提高线材在高磁场下的载流能力。MgB2/Nb/Cu superconducting wires were fabricated by two-step PIT process using dry Mg and B powders and doping SiC（40 ～45 nm）.The phase structure,microstructure was investigated by X-ray diffraction,scanning electronic microscopy.The resistivity temperature curves of MgB2 wires were measured by standard four-probe method.The results show that heat treatment temperature has a significant effect on the microstructure of wires,and appropriate sintering temperature increases the amount of C atoms diffusing into the lattice substitution for B atoms.The C substitution level is up to 3.73% at 750 ℃× 2 h.MgB2 superconducting wires fabricated by two-step PIT method can effectively introduce into C substitution for B position to enhance current-carrying capacity under high magnetic field.

关 键 词：MGB2超导线材 烧结温度 微观结构 超导电性 

分 类 号：TB333[一般工业技术—材料科学与工程]