Improvement of superconducting properties in high-critical-temperature oxide superconducting composite tapes using multiscale approach

利用多尺度方法提高高临界温度氧化物超导复合带的超导性能

• 批准号: 16360053
• 负责人: HOJO Masaki
• 金额: $ 9.28万
• 依托单位: KYOTO 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 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16360053/
• 关键词: High Tc superconducting material; Composite materials; Bi2223; Thermal residual stress; Thermal history; Critical current; Filament fracture; Void volume fraction; 臨界電流; ボイド率

A new measurement method with higher accuracy was developed for mechanical properties of mesoscopic components in Bi2223/Ag/Ag alloy high-critical-temperature oxide superconductors. Then, mesoscopic stress and strain states under thermal and mechanical loading were analyzed for newly developed superconducting tapes with the controlled-overpressure sintering method. The correlation between the deformation and superconductivity were studied from the viewpoints of design optimization of composite tapes. The results are summarized as follows :(1)Direct measurement of elastic modulus of filament using Ag alloy removed tapeTensile tests were carried out for composite tapes from which Ag alloy component was completely removed. Bi2223 filaments carry almost the entire load in Ag alloy removed tapes because the yield strength and the coefficient of work hardening of Ag are quite low, and the volume fraction of Bi2223 filament is about twice as much as that of Ag. Then, the elastic modulus of Bi … More 2223 filament is simply calculated from the stress-strain curve of Ag alloy removed tapes where the Ag component stress is over the yield strength. In other words, this proposed method gives nearly direct measurement of Bi2223 filament properties. The obtained filament elastic moduli,160 to 170 GPa, are much higher than those of conventional Bi2223/Ag/Ag alloy tapes. The filament elastic modulus for conventional tapes also agreed with that obtained by extracted Bi2223 filaments. The controlled-overpressure process dramatically increases the filament modulus. The difference in filament moduli were minimal though the critical current increase.(2)Direct measurement of fracture strain of filament using Ag alloy removed tapeSince the yield strength and the coefficient of work hardening of Ag are quite low, the thermal residual strain of Bi2223 filament is estimated as 0.004% at most. This value is about 5% of the fracture strain of Ag alloy removed tapes. Then, the residual strain of filament can be ignored in the evaluation of the fracture strain of filament, and the fracture strain of filament is directly obtained by the fracture strain of Ag alloy removed tapes.(3)Accuracy of measured fracture strain of filament in compositesThe simultaneous measurement of mechanical and superconducting properties of tapes at 77K indicated that the filament fracture occurred slightly before the final tape fracture. Taking into account this fact and all of the thermal history, the stress-strain curves of composite tapes were summing up. Here, the stress-strain curves of Ag alloy were estimated by using Vickers hardness data of its component. The good agreement between experiment and simulation indicated that the filament fracture strain evaluated by the Ag alloy removed method agreed well with that in composite tapes.(4)Effect of processing method on fracture strain of filamentThe filament fracture strains, about 0.08%, are almost the same without respect to the fabrication method of Bi2223/Ag/Ag alloy tapes. Less

开发了一种具有较高水平的新测量方法，用于在BI2223/AG/AGH-Criencation-Critical-临界氧化物超导体中的中镜分量的机械性能。烧结方法是从复合磁带的设计圆锥形的角度研究的变形和超导性的。屈服强度和工作硬化Ag的系数比Ag的弹性模量的较低。年份的强度。传统磁带的弹性模块化也与提取的BI2223丝所获得的弹性磁带同意。 BI2223的菌株最多估计为0.004％，然后去除Ag合金菌株。 AG合金的断裂应变去除磁带。（3）在组合中测量的丝菌株的精度同时测量了77K磁带的机械和超导性特性，表明Thelament filecture发生在触觉之前。在这里总结一下磁带。通过使用良好的一致性实验和仿真指示thacture thacture thacture thacture thacture thacture通过合金删除的方法在复合磁带中吻合了。

项目成果

Analysis of mesoscopic stress states with delamination and their relation to critical current under bending deformation in Bi2223/Ag superconducting composite tapes

• DOI: 10.1088/0953-2048/18/12/022
• 发表时间: 2005-12
• 期刊: Superconductor Science and Technology
• 影响因子: 3.6
• 作者: M. Hojo;M. Nakamura;Mototsugu Tanaka;T. Adachi;M. Sugano;Shojiro Ochiai;K. Osamura

Influence of Non-uniform Fiber Arrangement on Tensile Fracture Behavior of Unidirectional Fiber/epoxy Model Composites

纤维不均匀排列对单向纤维/环氧树脂模型复合材料拉伸断裂行为的影响

• 发表时间: 2005
• 期刊: Composite Interfaces 12・3-4
• 作者: Hobbiebrunken;T.;Hojo;M.;Adachi;T.;Jong;C.D.;Fiedler;B.;Masaki HOJO;Masaki HOJO;Shojiro OCHIAI;Thomas HOBBIEBRUNKEN;Mototsugu TANAKA
• 通讯作者: Mototsugu TANAKA

Direct measurement of elastic modulus of Nb3Sn using extracted filaments from superconducting composite wire

使用从超导复合线材中提取的细丝直接测量 Nb3Sn 的弹性模量

• 发表时间: 2006
• 期刊: Physica C : Superconductivity and its applications 445-448
• 作者: Hojo;M.;Matsuoka;I.;Hashimoto;M.;Tanaka;M.;Sugano;M.;Ochiai S.;Miyashita;K.
• 通讯作者: K.

Damage Evolution under Bending and Tensile Stresses and Its Influence on Critical Current of Bi2223/Ag Superconducting Composite Tape

Bi2223/Ag超导复合带在弯曲和拉伸应力下的损伤演化及其对临界电流的影响

• 发表时间: 2004
• 期刊: Journal of Nuclear Materials 329-333
• 作者: Hojo;M.;Nakamura;M.;Tanaka;M.;Adachi;T.;Sugano;M.;Ochiai;S.;Osamura;K.;Masaki HOJO;Shojiro OCHIAI
• 通讯作者: Shojiro OCHIAI

Influence of Delamination Location on Mesoscopic Stress State and Critical Current under Bending Deformation in Bi2223/Ag Superconducting Composite Tapes

分层位置对Bi2223/Ag超导复合带弯曲变形下细观应力状态和临界电流的影响

• 发表时间: 2005
• 期刊: Physica C : Superconductivity and its applications 426-431,Part 2
• 作者: Hobbiebrunken;T.;Hojo;M.;Adachi;T.;Jong;C.D.;Fiedler;B.;Masaki HOJO;Masaki HOJO
• 通讯作者: Masaki HOJO