【摘要】 采用进口喷雾热分解设备制备了Bi-2223前驱粉末,成相烧结后采用粉末装管法制备Bi-2223多芯线材.在线材轧制前对多芯线材进行低氧气氛热处理,然后再进行轧制以及后续的带材烧结.通过对低氧环境下,在不同热处理温度条件下烧结粉末的XRD谱线进行分析,发现粉末在740～750℃就可以实现Bi-2212四方相到正交相的转变,形成(Bi,Pb)-2212相.随后对多芯线材芯丝在低氧处理前后的微观硬度进行测试,发现低氧处理后银层和粉末的微观硬度均明显降低.最后采用标准的四引线法测量了线材低氧退火后轧制带材和未退火轧制带材的载流性能.结果表明,经过低氧处理的带材性能明显降低,原因可能是正交相线材在轧制时出现大量的裂纹缺陷,由于缺少富铅相弥合加工缺陷,导致最终带材载流性能降低.更多还原

【Abstract】 In this paper, Bi-2223 precursor powder was prepared by imported spray pyrolysis equipment. Bi-2223 multi-core wires were prepared by powder-in-tube process after phase sintering. The multi-core wires were heat treated in low oxygen atmosphere before rolling, and then rolled and subsequently sintered. The XRD spectra of the sintered powders were analyzed under the conditions of low oxygen and different heat treatment temperatures. It was found that Bi-2212 powders could transform from tetragonal phase to orthogonal phase at 740-750 ℃, and forming(Bi, Pb)-2212 phase. Subsequently, the microhardness of multi-core wire before and after hypoxia treatment was tested, and it was found that the microhardness of silver layer and powder after hypoxia treatment were significantly reduced. Finally, the current carrying capacity of the rolled tape after low oxygen annealing and the unannealed rolled tape were measured by standard four-lead method. The results show that the properties of the tapes treated by hypoxia are obviously reduced. The reason may be that there are a lot of cracks in the orthogonal phase wire during rolling. Due to the lack of lead-rich phase filling defects, the current carrying capacity of tape is reduced.更多还原