Abstract
The metallurgical reactions occurring during partial melting of the Zr-bearing YBCO composite superconductors have been investigated in detail by analyzing the DTA, XRD spectra and SEM micrographs of samples subjected to various heat treatments. It is shown that Zr reacts preferentially with Ba to form BaZrO3. As a result, the 123-phase is partially disintegrated and yields CuO and the 211-phase as by-products. The CuO phase in contact with the 123-phase lowers the melting point of the 123-phase to 970°C. The Zr-bearing YBCO sample annealed above 970°C melts partially and contributes to the reduction of voids. In addition, fine BaZrO3 particles precipitated along the grain boundaries form complicated three-dimensional networks. This skeletonlike structure prevents the sample from collapsing during partial melting and reinforces the mechanical strength of composites.
| Original language | English |
|---|---|
| Pages (from-to) | 1760-1764 |
| Number of pages | 5 |
| Journal | Japanese Journal of Applied Physics |
| Volume | 31 |
| Issue number | 6 R |
| DOIs | |
| Publication status | Published - 1992 Jan 1 |
| Externally published | Yes |
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Keywords
- Flexural strength
- Microstructure
- Superconducting composites
- Thermal analysis
- Zr-YBCO
ASJC Scopus subject areas
- Engineering(all)
- Physics and Astronomy(all)
Cite this
Metallurgical Reactions and Their Relationships to Enhanced Mechanical Strength in Zr-Bearing YBCO Composite Superconductors. / Oka, Tetsuo; Itoh, Yoshitaka; Yanagi, Yousuke; Tanaka, Hidehiko; Takashima, Shin ichi; Mizutani, Uichiro.
In: Japanese Journal of Applied Physics, Vol. 31, No. 6 R, 01.01.1992, p. 1760-1764.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Metallurgical Reactions and Their Relationships to Enhanced Mechanical Strength in Zr-Bearing YBCO Composite Superconductors
AU - Oka, Tetsuo
AU - Itoh, Yoshitaka
AU - Yanagi, Yousuke
AU - Tanaka, Hidehiko
AU - Takashima, Shin ichi
AU - Mizutani, Uichiro
PY - 1992/1/1
Y1 - 1992/1/1
N2 - The metallurgical reactions occurring during partial melting of the Zr-bearing YBCO composite superconductors have been investigated in detail by analyzing the DTA, XRD spectra and SEM micrographs of samples subjected to various heat treatments. It is shown that Zr reacts preferentially with Ba to form BaZrO3. As a result, the 123-phase is partially disintegrated and yields CuO and the 211-phase as by-products. The CuO phase in contact with the 123-phase lowers the melting point of the 123-phase to 970°C. The Zr-bearing YBCO sample annealed above 970°C melts partially and contributes to the reduction of voids. In addition, fine BaZrO3 particles precipitated along the grain boundaries form complicated three-dimensional networks. This skeletonlike structure prevents the sample from collapsing during partial melting and reinforces the mechanical strength of composites.
AB - The metallurgical reactions occurring during partial melting of the Zr-bearing YBCO composite superconductors have been investigated in detail by analyzing the DTA, XRD spectra and SEM micrographs of samples subjected to various heat treatments. It is shown that Zr reacts preferentially with Ba to form BaZrO3. As a result, the 123-phase is partially disintegrated and yields CuO and the 211-phase as by-products. The CuO phase in contact with the 123-phase lowers the melting point of the 123-phase to 970°C. The Zr-bearing YBCO sample annealed above 970°C melts partially and contributes to the reduction of voids. In addition, fine BaZrO3 particles precipitated along the grain boundaries form complicated three-dimensional networks. This skeletonlike structure prevents the sample from collapsing during partial melting and reinforces the mechanical strength of composites.
KW - Flexural strength
KW - Microstructure
KW - Superconducting composites
KW - Thermal analysis
KW - Zr-YBCO
UR - http://www.scopus.com/inward/record.url?scp=0026881540&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0026881540&partnerID=8YFLogxK
U2 - 10.1143/JJAP.31.1760
DO - 10.1143/JJAP.31.1760
M3 - Article
VL - 31
SP - 1760
EP - 1764
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
SN - 0021-4922
IS - 6 R
ER -