热分析技术在Nb_3Sn超导材料扩散热处理中的应用

Application of thermal analysis technology to diffusion heat treatment processing of Nb_3Sn multifilamentary superconductors

采用包括差示扫描量热分析(DSC)和热重分析(TG)在内的热分析方法,研究了Nb3Sn超导材料扩散热处理过程。以热分析数据为依据,对Nb3Sn低温超导材料样品进行了真空热处理。通过X射线衍射(XRD)和扫描电子显微镜(SEM)分析了Nb3Sn导线组织结构演变。结果表明,通过热分析技术确定了Nb3Sn超导线材的热处理温度范围,Nb3Sn样品在670℃加热得到了组织均匀细小的超导相结构。低温条件下的临界电流测试证明了经过热处理的NbSn导线具备了明显的超导性能。

Thermal analysis technologies,including differential scanning calorimetry（DSC）and thermal gravity analysis（TG）,were used to studying the heat treatment diffusion processing of Nb3Sn multifilament superconductors.The Nb3Sn wires were heat treated in vacuum according to the thermal analysis results.The microstructure evolution of Nb3Sn superconductors was analyzed using X-ray diffraction and scanning electron microscopy.The results show that the heat treatment temperature range can be obtained through thermal analysis technology.The fine grain structured Nb3Sn multifilament superconductors were fabricated successfully during the heat treatment at 670 ℃.The critical current test results confirmed that heat treated conductors possess superconductivity under liquid helium temperature condition.