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Effects of Temperature and Strain Rate on the Plastic Deformation of Fully Dense Polycrystalline Y 1 Ba 2 Cu 3 O 7− x Superconductor
Author(s) -
Bussod Gilles,
Pechenik Alexander,
Chu Chungtse,
Dunn Bruce
Publication year - 1989
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1989.tb05966.x
Subject(s) - materials science , crystallite , orthorhombic crystal system , superconductivity , electrical resistivity and conductivity , anisotropy , strain rate , deformation (meteorology) , stress (linguistics) , condensed matter physics , crystallography , composite material , mineralogy , metallurgy , crystal structure , chemistry , optics , linguistics , physics , philosophy , engineering , electrical engineering
The knowledge of the steady‐state stress for plastic deformation as a function of temperature and strain rate is essential for hot‐forming superconducting material into commercially useful shapes. In this paper, results are presented on the experimental determination of the rheology of fully dense polycrystalline Y 1 Ba 2 Cu 3 O 7−x superconducting material at temperatures ranging from 750° to 950°C and strain rates of 10 −4 , 10 −5 , and 10 −6 s −1 . The data are best fitted by a power law: ε(s −1 )=8.9 × 10 −17 . (s −1 ) σ 2.5 (Pa) exp [−2.01 × 10 5 (J·mol −1 )|RT]. X‐ray analysis shows that the superconducting material retains its phase composition after nearly 70% total strain of the sample. A strong anisotropy in the resistivity of the deformed samples is observed because of the development of a preferred orientation of the a or b axis of Y 1 Ba 2 Cu 3 O 7−x orthorhombic perovskite single crystals perpendicular to the principal maximum compressive stress.