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multi-directional-forging
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Modeling of dislocation density and strength on rheoforged A356 alloy during multi-directional forging
, Article Computational Materials Science ; Vol. 81 , 2014 , pp. 284-289 ; Saei, M ; Kazeminezhad, M ; Dodangeh, A ; Sharif University of Technology
Abstract
In this study, a hybrid model is presented to predict the dislocation density and strength evolution of the rheoforged non-dendritic A356 alloy during multi-directional forging. Regarding the characteristics of non-dendritic A356 alloy, combination of Shear Lag and Nes models is used for the eutectic structure, and Nes model is used for the α-Al globular phase. The aspect ratio variations of Si particles in eutectic structure during 3 passes of multi-directional forging do not change the model predictions, significantly. Model predictions on shear stress are in good agreement with experimental results of shear punch test
On the solution treatment of severely deformed AA2024-O and subsequent natural aging
, Article Journal of Materials Research and Technology ; Volume 20 , 2022 , Pages 1558-1569 ; 22387854 (ISSN) ; Kazeminezhad, M ; Sharif University of Technology
Elsevier Editora Ltda
2022
Abstract
In this research, the effect of applying severe strain before solid solution treatment (SST) for AA2024-O was studied. Providing concurrent insights into solutionizing behavior and microstructural evolution corresponding to hardness is important. Multi-directional forging (MDF) was used as a severe plastic deformation (SPD) method. After applying SST on MDFed (4 passes) and as-annealed samples, natural aging (NA) was used as the following treatment to examine the role of severe strain on the solutionizing behavior. In most previous attempts, SPD has been used after SST, but one of the innovations of the present work is the study of SPD before SST. Experimental results show that adding a...
Effect of concurrent precipitation on the texture evolution during continuous heating of multi directionally forged solution treated Al-Cu-Mg alloy
, Article Materials Characterization ; Volume 131 , 2017 , Pages 399-405 ; 10445803 (ISSN) ; Kazeminezhad, M ; Logé, R ; Sharif University of Technology
Abstract
Concurrent precipitation in an age hardenable aluminum alloy determines recrystallization behavior especially grains structure and recrystallization texture during continuous heating. In this study, to investigate the effect of concurrent precipitation on the recrystallization texture and grains structure, a solution treated Al-Cu-Mg alloy has been multi-directionally forged at room temperature and continuously heated with different heating rates (800, 1600 and 2500 K·min− 1) up to 450 °C using Gleeble 3800 thermo-mechanical simulator. At lower heating rates (800 K·min− 1), Goss texture component {110} 〈001〉 (Φ1 = 90°/0°, Φ = 90°/45°, Φ2 = 45°/90°) is developed during continuous heating and...
The effect of strain rate on multi-directional forged aluminum: examining the experimental data and modeling results
, Article Materials Chemistry and Physics ; Volume 239 , 1 January , 2020 ; Kazeminezhad, M ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
In this study, multi-directional forging (MDF) as a severe plastic deformation method, annealing, and compression test at different strain rates are applied on pure aluminum. One of the main observations is when the number of MDF passes is increased, the hardness is risen. The most noticeable reduction in hardness occurs when the MDFed samples are annealed at 350 and 450 °C. Moreover, increasing the number of MDF passes and the strain rate of the compression test cause the increase in the yield stress of the samples. If the MDFed samples are non-annealed or if they are annealed at a maximum temperature of 250 °C, the effect of an increase in the number of passes on the yield stress is more...
Heating rate effect on particle stimulated nucleation and grains structure during non-isothermal annealing of multi-directionally forged solution treated AA2024
, Article Materials Characterization ; Volume 127 , 2017 , Pages 317-324 ; 10445803 (ISSN) ; Kazeminezhad, M ; Logé, R ; Sharif University of Technology
Elsevier Inc
2017
Abstract
Particle stimulated nucleation (PSN) is one of the important mechanisms of recrystallization which is investigated in this research during non-isothermal annealing of multi-directionally forged solution treated aluminum alloy 2024. Non-isothermal annealing is performed up to temperatures of 380 °C and 450 °C at heating rates of 10, 100 and 200 K·min− 1 using a Gleeble 3800 thermo-mechanical simulator. In order to investigate the microstructure, field emission gun scanning electron microscope (FEG-SEM) equipped with electron backscatter diffractometer (EBSD) and differential scanning calorimetry (DSC) are utilized. The results show that the heating rate has a significant effect on the PSN and...
Mechanical behavior and texture development of over-aged and solution treated Al-Cu-Mg alloy during multi-directional forging
, Article Materials Characterization ; Volume 135 , 2018 , Pages 221-227 ; 10445803 (ISSN) ; Kazeminezhad, M ; Logé, R ; Sharif University of Technology
Elsevier Inc
2018
Abstract
The effects of initial heat treatments, i.e. solution treating and over ageing, on deformation behavior of an age hardenable Al-Cu-Mg alloy, including mechanical properties and texture evolution, during multi-directional forging (MDF) are investigated. Hardness measurements, electron back scatter diffraction (EBSD) maps, and differential scanning calorimetry (DSC) are carried out. Mechanical behaviors of the alloy in terms of compressive stress and hardness test after MDF are investigated. In both solution treated and over-aged alloys, the compressive stress during MDF shows an increase up to the second pass, and by further straining the flow stress is decreased. However, shear and...
Effects of non-isothermal annealing on microstructure and mechanical properties of severely deformed aluminum samples: Modeling and experiment
, Article Transactions of Nonferrous Metals Society of China (English Edition) ; Volume 29, Issue 6 , 2019 , Pages 1127-1137 ; 10036326 (ISSN) ; Kazeminezhad, M ; Sharif University of Technology
Nonferrous Metals Society of China
2019
Abstract
In order to investigate the evolution of microstructure and flow stress during non-isothermal annealing, aluminum samples were subjected to strain magnitudes of 1, 2 and 3 by performing 2, 4 and 6 passes of multi-directional forging. Then, the samples were non-isothermally annealed up to 150, 200, 250, 300 and 350 °C. The evolution of dislocation density and flow stress was studied via modeling of deformation and annealing stages. It was found that 2, 4 and 6 passes multi-directionally forged samples show thermal stability up to temperatures of 250, 250 and 300 °C, respectively. Modeling results and experimental data were compared and a reasonable agreement was observed. It was noticed that...
Flow stress of 2024 aluminum alloy during multi-directional forging process and natural aging after plastic deformation
, Article Materials Chemistry and Physics ; Volume 254 , 2020 ; Kazeminezhad, M ; Shadkam, A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
The hardening behavior of heat treatable alloys during deformation is attributed to three mechanisms of forest dislocations, solid solution and precipitation hardening which hinder the motion of dislocations and increase the density of statistically stored dislocation. In this paper, a model for the flow stress of a 2024 heat treatable aluminum alloy during plastic deformation is developed combining the superposition of these three hardening mechanisms. This model was then implemented into the finite element model in order to evaluate the evolution of the flow stress of 2024 aluminum alloy during multi-directional forging (MDF). Subsequently, an equation is developed for evaluating the...
Improved corrosion resistance and mechanical properties of biodegradable Mg-4Zn-xSr alloys: effects of heat treatment, Sr additions, and multi-directional forging
, Article Journal of Materials Research and Technology ; Volume 20 , 2022 , Pages 3363-3380 ; 22387854 (ISSN) ; Alizadeh, R ; Mahmudi, R ; Sharif University of Technology
Elsevier Editora Ltda
2022
Abstract
The effects of Sr additions, heat treatment (T4 and T6), and multi-directional forging on the microstructural evolution, mechanical properties and biodegradability of Mg-4Zn-xSr alloys were investigated. Corrosion behavior of the alloys was evaluated by the polarization and hydrogen evolution tests. Shear punch and hardness tests were employed to determine the mechanical properties. It was found that mechanical properties and corrosion resistance of the as-cast Mg-4Zn alloy increased by 0.3 wt% Sr addition. However, further increasing the Sr content not only did not improve the mechanical strength, but also had detrimental effects on the corrosion resistance, due to the increased size and...