Abstract
Stoichiometric MgAl2O4 spinel was deformed in compression at temperatures from 1790 to 1895‡ C and the dislocation structures analysed by transmission electron microscopy. {1 1 1}〈1 1 0〉 slip was observed on both the primary and cross-slip systems, and there was much secondary slip as well; all six 〈1 1 0〉 Burgers vectors were present in electron micrographs. This secondary slip leads to very high work-hardening rates, approximatelyΜ/70 at 1790‡ C, whereΜ is the shear modulus. Since it is known that deformation in nonstoichiometric (alumina-rich) spinel crystals occurs by {1 1 0}〈1 1 0〉 slip, the electrostatic and geometric aspects of 1/4 〈110〉 dislocations moving on {1 1 1} and {1 1 0} planes are considered in some detail. It is porposed that the octahedral cation vacancies present in non-stoichiometric spinel diffuse to dislocations during deformation and thus favour {1 1 0} slip.
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Mitchell, T.E., Hwang, L. & Heuer, A.H. Deformation in spinel. J Mater Sci 11, 264–272 (1976). https://doi.org/10.1007/BF00551437
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DOI: https://doi.org/10.1007/BF00551437