刘建军
,
徐克西
,
邱静和
,
吴兴达
无机材料学报
doi:10.3724/SP.J.1077.2008.00013
采用顶部籽晶熔融织构法制备了Y-Ba-Cu-O(YBCO)准单畴超导块材, 研究了Y2BaCuO5(Y211)粒子在块材中的分布及其对临界电流密度(Jc)和磁悬浮力性能的影响. 扫描电子显微镜(SEM)观察发现, Y211颗粒在准单畴超导块材中的分布是不均匀的. 实验结果表明, Y211平均粒径的大小与样品的磁悬浮力和临界电流密度成反比, Y211相粒子在母体中的分布越均匀, 粒子平均粒径越小, 越有利于提高临界电流密度和磁悬浮力. 对于φ20mm的YBCO单畴块材, 磁悬浮力可以达到33N(77K,0.55T), 临界电流密度达到6.6×104A/cm2.
关键词:
Y211粒子分布
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levitation force
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critical current density
郭强
,
李建峰
,
王庆相
,
闫凯娟
,
朱燕敏
,
刘建伟
,
刘向宏
,
冯勇
,
张平祥
低温物理学报
本文以高均匀性Nb47Ti合金锭和高纯无氧铜为原材料,制备了铜比为1.0,Φ0.846mm的MRI(Magnetic Resonance Imaging)用低铜比NbTi/Cu超导线.研究了最终应变和间隔应变对MRI用NbTi/Cu超导线微观组织和临界电流密度的影响.测试结果表明:时效3次时,最终应变在3.0～4.4之间,随最终应变增大,临界电流密度呈先增大而后降低,最终趋于稳定的变化规律;最终应变相同的条件下,增大间隔应变会导致临界电流密度的降低.经过工艺优化后,临界电流密度最高为3208A/mm2 (4.2K,5T,判据0.1μ上V/cm).微观组织观察表明:临界电流密度最高时,α-Ti沉淀相呈褶皱弯曲状,并弥散的分布在β-NbTi基体之上.
关键词:
NbTi/Cu超导线
,
临界电流密度
,
α-Ti沉淀相
,
最终应变
,
间隔应变
TANG Hong
,
XIANYU Ze
,
HU Qianli
,
QIAO Guiwen
,
WANG Yongzhong
,
ZHUANG Yuzhi1 1) Institute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang
,
China 2) Northeastern University
,
Shenyang
,
China Manuscript Received 7 March 1995
金属学报(英文版)
In this study, high-Tc YBaCuO superconductors with high Jc value were prepared using MTG(melting-textured growth) method. These superconductors with high density have Jc value in excess of 1.6×104 A/cm2 (77K, zero field) determined by using a d.c. standard four terminal method with the criterion of lμV/cm. The XRD and fractograph analysis revealed that the texture existed in whole MTG-processed YBaCuO sample which consists of the layered and plate-like grains of matrix phase YBa2Cu3Oy unidirectionally aligned along its (103) planes. The experimental results indicated that the connectivity between superconducting grains has been improved greatly and the weak-link problem has been overcome essentially.
关键词:
: YBaCuO high-Tc superconductor
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