Influence of the precursor powder composition on the microstructure and the critical current density of Bi2212 wires
Influence of the precursor powder composition on the microstructure and the critical current density of Bi2212 wires
复制标题
DOI：
10.1007/s10854-022-08914-2
复制
发表时间：
2022-08
期刊：
影响因子：
--
通讯作者：
Zhenbao Li;Guoqing Liu;G. Jiao;Xiaoyan Xu;Q. Hao;L. Bai;K. Yao;Chengshan Li
中科院分区：
文献类型：
--
作者：
Zhenbao Li;Guoqing Liu;G. Jiao;Xiaoyan Xu;Q. Hao;L. Bai;K. Yao;Chengshan Li
采用喷雾热解法制备了3种不同Bi含量的Bi2212 （BiaSr1.94Ca0.89Cu2O8+x,a= 2.17, 2.12, 2.07）粉体。由Bi2.07Sr1.94Ca0.89Cu2O8+ x粉末制成的线材具有最大的加工窗口（Tpwindow）和最高的je。在0.1 MPa O2条件下，在4.2 K/ MPa的自场烧结条件下，最终可获得jof 1187 A/mm2和jof 5805 A/mm2。该值比传统粉末成分Bi2.17Sr1.94Ca0.89Cu2O8+x制作的线材高39%。对导线的显微组织、相组成和载流性能进行了综合分析。主要结论如下：(1)DSC得到的Bi2212粉末的熔融温度范围（ΔT）可能是评价其成分均匀性的重要指标。ΔTmeant越低，粉末的成分均匀性越好，焊丝的tpwindow越大。(2)烧结丝中Bi2212的晶粒尺寸和织构均受Ag的影响。较大的Ag晶粒尺寸和较好的Ag织构有利于提高烧结丝中Bi2212的织构。(3)线材中保持Bi2212相的高纯度和高织构是保持高jc的关键因素。(4)首次利用微区XRD获得了Bi2212烧结丝的相组成、显微组织和织构。在今后的研究中将充分采用。上述结果为了解烧结丝的相演化和提高其载流性能提供了有意义的信息。
Three Bi2212 (BiaSr1.94Ca0.89Cu2O8+x,a= 2.17, 2.12, 2.07) powders with different Bi contents were made by the spray pyrolysis technology. The wire made from Bi2.07Sr1.94Ca0.89Cu2O8+xpowder had the largest processing window (Tpwindow) and the highestJe. It eventually heldJeof 1187 A/mm2andJcof 5805 A/mm2at 4.2 K/self-field sintered under 0.1 MPa O2. ThisJevalue was 39% higher than that of wires made from the traditional powder composition of Bi2.17Sr1.94Ca0.89Cu2O8+x. The microstructure, the phase composition, and the current-carrying property of the wires were analyzed comprehensively. The key conclusion was as follows: (1) The melting temperature range (ΔT) obtained from DSC for Bi2212 powder might be an important index to evaluate its composition homogeneity. The lower ΔTmeant better composition homogeneity of the powder and corresponded to a largerTpwindow for the wire. (2) The crystal size and the texture of Bi2212 in the sintered wires were both influenced by that of Ag. Both larger crystal size and better texture of Ag were beneficial to increase that of Bi2212 in the sintered wire. (3) Holding high phase purity and high texture of Bi2212 phase in the wires were key factors to hold highJc. (4) The micro-area XRD was used for the first time to obtain the phase composition, the microstructure, and the texture in Bi2212 sintered wires. It will be adopted sufficiently in the future study. The above results provided insightful information to understand both the phase evolution of the sintered wire and to improve its current-carrying property.