摘要
用高温X射线衍射、SEM-EDX分析、差热分析和目测法确定了Bi-Pb-Sr-Ca-Cu-O超导陶瓷烧结过程中的中间产物的熔融反应,并考察了这种反应对超导陶瓷显微组织和临界电流密度(J_c)的影响。上述综合研究表明,中间产物[30A相与(Sr_(1-x)Ca_x)_2PbO_4相]的熔融反应产生(Sr_(1-x)Ca_x)_2CuO_3相粗粒,形成成分偏析的显微组织,这是高温反应烧结导致低J_c超导陶瓷的原因。
The critical current densities and the microstructures of superconducting Bi-
Pb-Sr-Ca-Cu-O ceramics sintered at various temperatures were measured and cha-
racterized, and the melting of transient phases in the reactive sintering of super-
conducting Bi-Pb-Sr-Ca-Cu-O ceramics was investigated by high temperature X-ray
diffraction, SEM-EDX analysis, DTA and direct observation of melting. The
melting of transient phases [30A phase and (Sr_(1-x) Ca_x)_2PbO_4] results in the forma-
tion of large (Sr_(1-x)Ca_x)_2CuO_3 particles and inhomogeneous distribution of com-
ponents. The low critical current density of the superconducting ceramics sinte-
red at higher temperature results from the melting of transient phases.
关键词
陶瓷
超导陶瓷
烧结
铋铅锶钙铜氧
Bi-Pb-Sr-Ca-Cu-O
critical current density
sintering
high temperature X-ray diffraction
superconducting
