铋系高温超导粉体的制备

Fabrication of Bi-System High Temperature Superconducting Powder

首先采用喷雾热分解法制备了铋系超导粉体,然后对得到的粉体进行焙烧处理,焙烧时采用不同的工艺参数,包括温度、保护气体的氧分压等。利用XRD,SEM等分析手段,研究了焙烧后粉体的粒度分布,形貌,相组成及其均匀性等。最后,采用粉末套管法将焙烧后的超导粉体制备成单芯超导带材,在形变热处理后,带材样品获得了超过30A的临界电流。

The quality of Bi-2223/Ag tapes depends strongly on several process parameters, including the initial powder, the mechanical deformation, the annealing atmosphere and temperature as well as the annealing time. The properties of the initial powder have been proved to play an important role in determining the microstructure and properties of Bi-2223/Ag tapes, such as the phase composition, the relative content of lead oxide compounds, as well as the particle size and distribution. Bi-2223 powders were fabricated first by spray pyrolysis which were calcined later under different conditions, including temperature, oxygen partial pressure in atmosphere, Then the phase composition, particle size and microstructure of the as-calcined powders were analyzed by XRD and SEM. Finally, monofilament Bi-2223/Ag tape was fabricated by OPIT method using the resulting powders. After heat treatment, the critical current of the tape is up to 30A.