Elucidation of the critical current enhancement mechanism due to the repeated bending treatment for high-strength Nb_3Sn wires

阐明高强度Nb_3Sn线材反复弯曲处理的临界电流增强机制

基本信息

批准号：
16360145
负责人：
WATANABE Kazuo
金额：
$ 9.15万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2007
项目状态：
已结题

项目摘要

Research subjective was to understand the basic mechanism for the critical current enhancement effect due to the applying repeated bending strain at room temperature fur pre-reacted NbaSn strands and to find the important guiding principle for the manufacturing process of NbaSn strand cables, employing pre-reacted NbaSn strands.To apply the critical current enhancement effect for NbaSn strands with the repeated bending strain treatment, a test oil was prepared by NbaSn strands reinforced with CuNb composite, and the critical current enhancement was confirmed in the test coil applied by a large hoop stress. The SEM observation was carried out for NbaSn strand-directional filaments etched out from the repeated-bending-treatment sample. It is found that the repeated bending treatment introduces micro-crack defects into NbaSn filament cores, and that such micro-crack defects do not increase until a tolerated strain limit of 0.8 %, in the case of NbaSn strands with. CuNb reinforcement in the outer portion. The NbaSn strands with and without the prebending treatment were measured by the neutron diffraction, which is a high resolution and high intensity powder diffractmeter at KEK in Tsukuba. The residual strains for the prepared NbaSn strands with and without the prebending treatment reveal the clear difference in the lateral direction between the two. We succeeded in indicating the residual strain reduction for the repeated bend NbaSn directly by the neutron diffraction. This means that the important understandings for the critical current enhancement elect of Nb_3Sn strands were obtained.The three + four (3+4) strand cable Consisting of three Nb_3Sn strands and four stainless steel strands were fabricated to develop new NbaSn stand cables applying the critical current enhancement effect It is found that the prepared 3+4 strand cable surely maintains such enhancement in the practical strand cabling process.

研究主观是要了解由于在室温皮毛上施加重复弯曲应变而导致的临界电流增强效应的基本机制用CUNB复合材料加强的链，并在较大的箍应力施加的测试线圈中确认了临界电流增强。对从重复的弯曲处理样品中蚀刻出的NBASN链方向丝进行了SEM观察。已经发现，重复的弯曲处理将微裂缝缺陷引入NBASN细丝核，并且在与NBASN链的情况下，这种微裂缝缺陷直到耐受应变极限为0.8％，才会增加。外部的CUNB加固。通过有或没有预先处理治疗的NBASN链通过中子衍射测量，这是Tsukuba中KEK的高分辨率和高强度粉末衍射表。有和没有预先处理治疗的制备NBASN链的残留菌株显示两者之间横向方向的明显差异。我们成功地指示了由中子衍射直接直接通过中子衍射的重复弯曲NBASN的残留应变减少。这意味着，获得了对NB_3SN链的临界电流增强选举的重要理解。由三个NB_3SN链组成的三个+四（3+4）链电缆制造了四个不锈钢链，以开发出新的NBASN支架电缆，这些新的NBASN支架是应用了临界电流增强效应，该效果是在制定的3+4链条上的效果，以增强3链的效果。

项目成果

期刊论文数量（60）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Cryogen-Free Superconducting Magnet Fabricated by a React and Wind Method Employing Nb_<3>Sn Wires with CuNbTi Reinforcement

CuNbTi增强Nb_<3>Sn线反应风法制备无液剂超导磁体

DOI：
发表时间：
2004
期刊：
影响因子：
0
作者：
K. Watanabe;G. Nishijima;S. Awaji;K. Takahashi;K. Miyoshi;S. Meguro;M. Ishizuka and T. Hasebe
通讯作者：
M. Ishizuka and T. Hasebe

Progress and Challenges in Cryogen-Free Hybrid Magnets

无制冷剂混合磁体的进展和挑战

DOI：
发表时间：
2004
期刊：
影响因子：
0
作者：
K. Watanabe;T. Mitsuhashi;N. Nanato;S.B. Kim;S. Murase;G. Nishijima;K. Watanabe and K. Miyoshi;K. Watanabe
通讯作者：
K. Watanabe

Prebending Effects in Bronze Route Nb_<3>Sn Wires -Mechanism and Application-

青铜路线Nb_<3>Sn线的预弯效应-机理与应用-