Philosophical magazine. A/Philosophical magazine. A. Physics of condensed matter. Structure, defects and mechanical properties · 1978 · 55 citations · 11 references
Natural SciencesMaterials EngineeringMaterials ScienceCrystal StructureMechanical Behavior Of MaterialsStructural MaterialsDeformation MechanismsDislocation MechanicsDislocation TheoryFracture MechanicsPlastic DeformationStacking FaultsDislocation ClimbDislocationsEdge DislocationsPoint DefectsSpinel OxidesSpinel StructureStacking Fault EnergyTemperature Dependence Of Deformation
Abstract Depending upon the temperature at which spinel oxides are deformed, different dissociation configurations of dislocations have been observed. At elevated temperatures, edge dislocations are dissociated over several hundreds angstroms by a process involving climb of partials. At low temperatures, the long screw dipoles resulting from indentation tests suggest a classical dissociation of dislocations out of the preferred glide plane. These effects are compared to calculations of stacking-fault energy in the spinel structure. A good qualitative agreement is found whatever the dissociation mechanism. Quantitative agreement is satisfactorily obtained only in so far as glide dissociation is concerned. Discrepancies between calculated and observed climb dissociation suggest a strong interaction effect with point defects. The possible effects that such a dissociation dependence upon temperature has on deformation mechanisms in spinels are discussed.
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