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Ultrasonic evaluation of oxidation and reduction effects on the elastic behavior and global microstructure of YBa2Cu3O7-xUltrasonic velocity measurement techniques were used to evaluate the effects of oxidation and reduction on the elastic properties, global microstructure and oxygen content of the YBa2Cu3O(7-x) ceramic superconductor for samples ranging from 70 to 90 pct. of theoretical density. Bulk density, velocity, and elastic modulus generally increased with increasing oxygen content upon oxidation, and this behavior was reversible. Velocity image patterns were similar after oxidation and reduction treatments for a 90 pct. dense sample, although the velocity value at any given point on the sample was changed following the treatments. The unchanging pattern correlated with destructive measurements showing that the spatial pore distribution (fraction and size) was not measurably altered after the treatments. Changes in superconducting behavior, crystal structure, and grain structure were observed consistent with changes in oxygen content.
Document ID
19910018261
Acquisition Source
Legacy CDMS
Document Type
Technical Memorandum (TM)
Authors
Roth, Don J.
(NASA Lewis Research Center Cleveland, OH., United States)
Deguire, Mark R.
(Case Western Reserve Univ. Cleveland, OH., United States)
Dolhert, Leonard E.
(Grace, W. R. and Co., Columbia MD , United States)
Date Acquired
September 6, 2013
Publication Date
July 1, 1991
Subject Category
Quality Assurance And Reliability
Report/Patent Number
E-6282
NAS 1.15:104529
NASA-TM-104529
Accession Number
91N27575
Funding Number(s)
PROJECT: RTOP 506-43-11
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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