Mechanical properties and densification mechanism of powder-in-tube BaxK1−xFe2As2 superconductors. (1st May 2022)

• Record Type: Journal Article
• Authors: Han, Meng; Yao, Chao; Zhang, Xianping; Wang, Dongliang; Dong, Chiheng; Liu, Cong; Huang, He; Yang, Peng; Guo, Wenwen; Tu, Chang; Liu, Shifa; Liu, Xinyuan; Zhang, Qianjun; Zhang, Zhihao; Xie, Jianxin; Ma, Yanwei
• Is Part Of: Superconductor science & technology. Volume 35:Number 5(2022)
• Publication Date: 2022-05-01
• Subjects: iron-based superconductor -- BaK-122 -- density -- mechanical constitutive -- numerical simulation -- superconducting transport property; Superconductivity -- Periodicals; Superconductors -- Periodicals; 537.623
• DOI: 10.1088/1361-6668/ac4ba0
• Languages: English
• ISSNs: 0953-2048

Abstract

Abstract: Ba x K1− x Fe2 As2 (BaK-122) iron-based superconductors (IBSs) have been considered to be promising for high-field applications. The transport J c performance of BaK-122 wires and tapes is continuously enhanced by introducing advanced fabricating methods. The mass density of BaK-122 superconducting core in wires and tapes is important to the transport J c performance and related to the mechanical behavior during preparation. In this work, the mechanical property parameters including Poisson's ratio-density, yield strength-density, and elastic modulus-density of BaK-122 IBS powder were examined via uniaxial compression experiments. The density-dependent mechanical constitutive of BaK-122 was obtained for the first time. The relationship function between density and Vickers hardness of BaK-122 was established as HV0.05 = 0.0249 ρ 5.332 based on the numerical simulation of hardness testing, and a method for characterizing the BaK-122 core density was developed. It had been found the sheath materials and preparation method have great influences on the stress state of the BaK-122 core, and then affect the density. The densification mechanism and corresponding improvement method were revealed to provide guidance for preparing high-density BaK-122 wires and tapes. Finally, the generalized relationship between density and the superconducting transport J c was established according to lots of experimental data from multiple BaK-122 samples, which has confirmed the positive correlation of ρ core and J c . We comparatively discussed the various cold-work and heat-treatment processes used in our team for preparing the BaK-122 wires and tapes, and the critical factors affecting the transport performance were summarized.