The Influences of Powder Processing Variables on the Properties of Bi-2223/Ag Tapes

High-temperature superconducting (HTS) (Bi, Pb)
₂
Sr
₂
Ca
₂
Cu
₃
O
₁₀
/Ag superconducting tape (Bi-2223 tape) is made mainly by three process steps including preparation of precursor powder, mechanical deformation, and heat treatment of the tape. Recently, our main efforts have been made to improve the precursor powder. With nitrates and nitric acid as main starting materials, and using spray drying and other technology, an effective process of making precursor powder for Bi-2223 tape has been developed. This paper reports this process in detail and the influences of powder processing parameters on the tape properties, such as aliquation of composition, particle size, as well as residual oxynitride, carbon, and water. By optimizing powder preparation parameters, high-quality Bi-2223 tape with critical current of about 150 A (77 K, self field) was made.