A polycrystal plasticity model is proposed to predict the unique rolling texture of Cu/Nb nanostr... more A polycrystal plasticity model is proposed to predict the unique rolling texture of Cu/Nb nanostructured multilayers. At this length scale, the model accounts for the interface between Cu and Nb layers by computing the aggregate response of composite grains using a viscoplastic self–consistent scheme. Each composite grain is divided into Cu and Nb crystals with the interface parallel to the rolling plane, and compatibility and equilibrium are enforced across the interface. A latent hardening effect is introduced to account for the interaction between glide and interface dislocations. The latter are accumulated during slip transmission. This unconventional hardening confines the movement of glide dislocations by promoting symmetry of slip activities. Consequently, it slows development of the rolling texture for Cu/Nb nanolayers, and partially preserves the initial interface orientation defined by the Kurdjumov–Sachs relationship.
The microstructure and flow stress behavior of thermomechanically processed Al–Cu/Mg 2 Si in-situ... more The microstructure and flow stress behavior of thermomechanically processed Al–Cu/Mg 2 Si in-situ composite was studied emphasizing the evolution of primary and secondary reinforcement phases. Toward this end, the hot compression tests were conducted over the wide range of temperature (300–500 °C) and strain rate (0.001–0.1 s À 1). Both the temperature and strain rate are found to possess a significant effect on the microstructural characteristics where a considerable softening is identified specially at low temperature regime. Besides the occurrence of restoration processes (mainly particle stimulated nucleation) the dynamic evolution of the reinforcements is introduced as the main factors affecting the reported softening. In this regard, the mechanical fragmentation, thermal disintegration, micro-buckling, coalescence and spheroidization of the primary and secondary particles are quantitatively and qualitatively addressed through a comprehensive scanning electron microscopy studies.
A polycrystal plasticity model is proposed to predict the unique rolling texture of Cu/Nb nanostr... more A polycrystal plasticity model is proposed to predict the unique rolling texture of Cu/Nb nanostructured multilayers. At this length scale, the model accounts for the interface between Cu and Nb layers by computing the aggregate response of composite grains using a viscoplastic self–consistent scheme. Each composite grain is divided into Cu and Nb crystals with the interface parallel to the rolling plane, and compatibility and equilibrium are enforced across the interface. A latent hardening effect is introduced to account for the interaction between glide and interface dislocations. The latter are accumulated during slip transmission. This unconventional hardening confines the movement of glide dislocations by promoting symmetry of slip activities. Consequently, it slows development of the rolling texture for Cu/Nb nanolayers, and partially preserves the initial interface orientation defined by the Kurdjumov–Sachs relationship.
The microstructure and flow stress behavior of thermomechanically processed Al–Cu/Mg 2 Si in-situ... more The microstructure and flow stress behavior of thermomechanically processed Al–Cu/Mg 2 Si in-situ composite was studied emphasizing the evolution of primary and secondary reinforcement phases. Toward this end, the hot compression tests were conducted over the wide range of temperature (300–500 °C) and strain rate (0.001–0.1 s À 1). Both the temperature and strain rate are found to possess a significant effect on the microstructural characteristics where a considerable softening is identified specially at low temperature regime. Besides the occurrence of restoration processes (mainly particle stimulated nucleation) the dynamic evolution of the reinforcements is introduced as the main factors affecting the reported softening. In this regard, the mechanical fragmentation, thermal disintegration, micro-buckling, coalescence and spheroidization of the primary and secondary particles are quantitatively and qualitatively addressed through a comprehensive scanning electron microscopy studies.
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Papers by K. al-Fadhalah