Abstract
High-temperature deformation characteristics of YBa2Cu3O7−x oxide (YBCO) and YBa2Cu3O7−x/Ag composite (YBCO/Ag) in uniaxial compression have been investigated. A compression test was carried out at temperatures from 780–930°C at initial strain rates between 10−6 and 10−4 s−1. YBCO/Ag composites with fine, dense and equiaxed grains were compressed over 120% with no indication of failure at higher temperatures, and the strain-rate sensitivity exponent, m, was found to be about 0.42–0.46 between 890 and 930°C. They are considered to be one indication of superplasticity. The activation energy for deformation was 500–580 KJ mol−1. The specimens suffered grain growth slightly during the deformation at 930°C and the majority of growth might be a function of exposure time, temperature and silver content, but each grain maintained the equiaxed shape after extensive superplastic deformation. This is consistent with a grain-boundary sliding mechanism. The silver at grain boundaries acts to decrease the activation energy for deformation and promote the grain-boundary sliding.
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W. J. KIM, J. WOLFENSTINE and O. D. SHERBY, Acta Metall. Mater. 39 (1991) 199.
F. WAKAI, S. SAKAGUCHI and Y. MATSUNO, Adv. Ceram. Mater. 1 (1986) 259.
Y. MAEHARA and T. G. LANGDON, J. Mater. Sci. 25 (1990) 2275.
I. W. CHEN and L. A. XUE, J. Am. Ceram. Soc. 73 (1990) 2585.
P. E. REYES-MOREL, X. WU and I-Wei CHEN, in “Ceramic Superconductors II”, edited by M. F. YAN (American Ceramic Society, Westerville, OH, 1988) p. 590.
G. BUSSOD, A. PECHENIK, T. CHU and B. DUNN, J. Am. Ceram. Soc. 72 (1989) 137.
K. C. GORETTA, J. L. ROUTBORT, A. C. BIONDO and Y. GAO, J. Mater. Res. 15 (1990) 2766.
A. W. von STUMBERG, N. CHEN and K. C. GORETTA and J. L. ROUTBORT, J. Appl. Phys. 66 (1989) 2079.
Y. KODAMA and F. WAKAI, in “Advances in Superconductivity II”, (Springer, Tokyo, 1990) p. 113.
W. J. KANG, PhD thesis, Tohoku University, Japan (1992).
J. YUN, M. P. HARMER, Y. T. CHOU and O. P. ARORA, in “Superplasticity in Advanced Materials”, edited by S. HORI, M. TOKIZANE and N. FURUSHIRO (Japan Society for Research on Superplasticity, Osaka, 1991) p. 275.
O. A. KAIBYSHEV, R. M. IMAEV and M. F. IMAEV, Sov. Phys. Dokl. 34 (1989) 375.
B. C. HENDRIX, T. ABE, J. C. BOROFKA, P. C. WANG and J. K. TIEN, J. Am. Ceram. Soc. 76 (1993) 1008.
J. YUN, M. P. HARMER and Y. T. CHOU, Scripta Metall. Mater. 29 (1993) 267.
J. P. SINGH, H. J. LEU, R. B. POEPPEL, E. van VOORHEES, G. T. GOUDEY, K. WINSLEY and D. SHI, J. Appl. Phys. 66 (1989) 3154.
T. G. LANGDON, J. Metals (July) (1990) 8.
M. J. KRAMER and S. R. ARRASMITH, IEEE Trans. Magn. 27 (1991) 920.
F. WAKAI, H. KATO and S. SAKAGUCHI, J. Ceram. Soc. Jpn 94 (1986) 1017.
T. G. NIEH and J. WADWORTH, Mater. Res. Soc. Symp. Proc. 196 (1990) 331.
W. H. TUAN and J. M. WU, J. Mater. Sci. 28 (1993) 1409.
S. SAMAJDAR and S. K. SAMANTA, ibid. 27 (1992) 4709.
R. DUCLOS and J. CRAMPON, ibid. 6 (1987) 905.
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Kim, BC., Kim, JT. & Song, JT. Superplastic behaviour of YBa2Cu3O7−x/Ag superconductors. Journal of Materials Science 30, 3369–3375 (1995). https://doi.org/10.1007/BF00349881
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DOI: https://doi.org/10.1007/BF00349881