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ETMB model investigation of flow softening during severe plastic deformation
, Article Computational Materials Science ; Volume 46, Issue 4 , 2009 , Pages 902-905 ; 09270256 (ISSN) ; Kazeminezhad, M ; Sharif University of Technology
2009
Abstract
In this study, the flow softening of FCC materials through severe plastic deformation (SPD) is investigated using ETMB (Y. Estrin, L.S. Toth, A. Molinari, Y. Brechet) model. To do so, using the model, the equal channel angular pressing (ECAP) processes of two FCC materials, aluminum and copper, are investigated. The correlation between the recovery parameters of ETMB model (the dynamic recovery exponents and coefficients) and the intrinsic characteristics of the materials (the stacking fault energy (SFE) and melting point) is described and compared with the previous claims. © 2009 Elsevier B.V. All rights reserved
The Effect of Strain Rate on Multi-directional Forged Aluminum
, M.Sc. Thesis Sharif University of Technology ; Kazeminezhad, Mohsen (Supervisor)
Abstract
In this study, multi directional forging as a severe plastic deformation method is applied on pure aluminum at the different strain of 0.5, 1.5, 2.5, and 3.5. Annealing has been applied to samples at 150 C, 250 C, 350 C, and 450 C for one hour. In the next step, compressive test is carried out on MDFed and annealed MFDed pure aluminum through strain rate of 0.01 1/s, 0.001 1/s, and 0.0001 1/s. Based on experimental data, when the number of MDF is passes increased, because of increasing the dislocation density and grain boundary area, yield stress is increased. As an example, the yield stress of 7 passed MDFed aluminum is 2.25 times of that of 1 passes MDFed aluminum. Annealing would...
Modeling of induced empirical constitutive relations on materials with FCC, BCC, and HCP crystalline structures: Severe plastic deformation
, Article International Journal of Advanced Manufacturing Technology ; Volume 47, Issue 9-12 , April , 2010 , Pages 1033-1039 ; 02683768 (ISSN) ; Hosseini, E ; Sharif University of Technology
2010
Abstract
In this study, empirical constitutive relations of materials with different crystalline structures through severe plastic deformation are introduced. Here, for each material, an optimized empirical relation is chosen by fitting some empirical relations on the results achieved from a dislocation- based constitutive model. In this work, four modes of empirical relations are fitted on the results of modified Estrin-Toth-Molinari-Brechet constitutive model for four materials with different crystalline structures (Al, Cu, Ta, and Zr). The obtained relations for the materials can be usable in commercial finite element codes
Dislocation density and flow stress modeling of nanostructured Al-SiC p composite during accumulative roll bonding
, Article Computational Materials Science ; Volume 67 , February , 2013 , Pages 359-363 ; 09270256 (ISSN) ; Saei, M ; Kazeminezhad, M ; Sharif University of Technology
2013
Abstract
In order to investigate the dislocation structure and flow stress evolution of Al-SiCp composite during ARB process, a comprehensive model which describes the evolution of dislocation density is needed. Dislocation density, microstructure and flow stress evolution of Al-SiCp composite are predicted considering the ETMB model, strain and strain rate achieved from the mechanical model of ARB process and shear modulus calculated from the composite model. In addition, models' parameters such as dislocation generation parameters are modified due to the effect of SiC particles. The predicted results are in good agreement with experimental data