Residual Stress in Nb3Sn Superconductor Strand Introduced by Structure and Stoichiometric Distribution After Heat Treatment
Residual Stress in Nb3Sn Superconductor Strand Introduced by Structure and Stoichiometric Distribution After Heat Treatment
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结构和化学计量分布对Nb3Sn超导绞线热处理后的残余应力
DOI：
10.1109/tasc.2017.2685500
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发表时间：
2017
影响因子：
1.8
通讯作者：
Cheng Junsheng
中科院分区：
文献类型：
--
作者：
Jin Peng;Li Lankai;Li Xide;Wang Qiuliang;Cheng Junsheng
Nb_3Sn是一种被广泛采用的超导材料，具有脆性和应变敏感性。许多研究已经预料到这些缺陷会受到Nb3Sn超导相与母体之间热膨胀失配的很大影响。对热处理后的青铜绞线进行了室温下的X射线衍射应力分析，发现其平均轴向残余应力为−135.7 Mpa，波动幅度约为30 0 Mpa。我们建立了弹性分析模型，并解释了整体压缩。这种相当大的应力波动现象可能源于扩散，这一点得到了电子探针微观分析结果的支持。这项工作突出了体积变形和组分分布对超导线束应力状态的重要性，并可以补充热失配模型。
Nb3Sn, a widely adopted superconducting material, suffers from fragility and sensitivity to strain. Many studies have anticipated these drawbacks to be greatly influenced by thermal expansion mismatch between the Nb3 Sn superconducting phase and matrix. We conducted X-ray diffraction (XRD) stress analysis on a heat treated bronze strand at room temperature and found that its average axial residual stress was −135.7 MPa with fluctuation of about 300 MPa. We developed an elastic analytical model and explained the overall compression. The considerable stress fluctuation phenomenon may originate from diffusion, which was supported by electron probe microanalysis results. This work highlights the importance of volume transmutation and component distribution on the stress status of a superconducting strand and can supplement the thermal mismatch model.