Effect of lead content on phase evolution and microstructural development in Ag-clad Bi-2223 composite conductors

Technical Report · Sat Feb 01 04:00:00 EST 1997

DOI:https://doi.org/10.2172/446397· OSTI ID:446397

Merchant, N N; Maroni, V A; Fischer, A K; Dorris, S E; Zhong, W; Ashcom, N ^[1]

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1. Argonne National Lab., IL (United States). Chemical Technology Div.

A two powder process was used to prepare silver-sheathed monofilamentary Bi{sub 1.8}Pb{sub x}Sr{sub 1.98}Ca{sub 1.97}Cu{sub 3.08}O{sub y} (Bi-2223) tapes with varying lead contents, x, from 0.2 to 0.5. The resulting tapes were subjected to thermomechanical processing and then characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive x-ray analysis (EDX). Layered phase texture was accessed using image analysis software on scanned SEM micrographs. Transport currents were measured at 77 K and zero field by the four-probe method. It was found that tapes with low lead content (X = 0.2 and 0.25) showed incomplete conversion to Bi-2223, had small grain size and poor c-axis texture. Tapes having higher lead content (x = 0.4 and 0.5) also showed incomplete conversion and the presence of lead-rich secondary phases. Tapes with lead content x = 0.3 and 0.35 showed complete conversion to Bi-2223, and had the least amount of secondary phases, the best c-axis texture, and the highest transport current (j{sub c}). The carbon content of the precursor powder also had a strong influence on secondary-phase chemistry.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: USDOE Assistant Secretary for Energy Efficiency and Renewable Energy, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 446397
• Report Number(s): ANL/CMT/CP--90759; CONF-970201--18; ON: DE97003236
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BISMUTH OXIDES
CALCIUM OXIDES
COPPER OXIDES
CRITICAL CURRENT
EXPERIMENTAL DATA
LEAD OXIDES
METALLURGICAL EFFECTS
MICROSTRUCTURE
PHASE STUDIES
SILVER
STRONTIUM OXIDES
SUPERCONDUCTING COMPOSITES
SUPERCONDUCTIVITY
TEXTURE