List of articles (by subject)
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Open Access Article
1 - Accumulative press bonding: a novel process for manufacturing Al/ZnO metal matrix nanocomposites
سجاد امیرخانلو محمد ابراهیم باجغلی مصطفی کتابچی نادر پروین -
Open Access Article
2 - Investigation of Dynamic and Static Restoration in Hot Deformation of SP-700 Titanium Alloy
Amir hosein Sheikhali Maryam Morakkabti seyed mahdi abbasiIn order to investigation of dynamic and static restoration of SP-700 alloy, in this study continuous and interrupted hot torsion tests carried out at 850 and 1000ºC at different pass-strains and inter-pass times. The dominant mechanism in hot deformation at 1000&d MoreIn order to investigation of dynamic and static restoration of SP-700 alloy, in this study continuous and interrupted hot torsion tests carried out at 850 and 1000ºC at different pass-strains and inter-pass times. The dominant mechanism in hot deformation at 1000°C is dynamic recrystallization (DRX) and consequently the entire microstructure comprises equiaxed grains, whereas at 850°C serration and tanglement of the grain boundaries were observed. Nevertheless, the microstructure of sample twisted at 850°C, indicates the occurrence of DRX and the formation of very fine grains. The mechanism of the formation of recrystallized grains in the vicinity of grain boundaries and triple points is bulging. With an increase in pass-strain (ε=0.5) at 1000°C, due to the increase in driving force for nucleation and growth of new grains, the kinetics of static restoration increases. In fact, at 850°C, in addition to static restoration there is another factor contributing in fractional softening which is β to α phase transformation. Manuscript profile -
Open Access Article
3 - Investigation of the Size Effect in Compression Test by Combined Hill-Taylor Theory
Faraz Rahimzadeh Lotfabad Ramin EbrahimiIn this paper, first the crystal plasticity notions developed by Taylor are combined with the mathematical form of Hill’s yield criterion for the anisotropic materials and a novel model is developed for description of mechanical response of grains in a specimen, b MoreIn this paper, first the crystal plasticity notions developed by Taylor are combined with the mathematical form of Hill’s yield criterion for the anisotropic materials and a novel model is developed for description of mechanical response of grains in a specimen, based on their orientation. The advantage of the proposed model compared to other crystal plasticity finite element techniques is that in the conventional crystal plasticity codes, the deformation taken to be consisted of slip on all slip systems which is not valid assumption, yet here, the deformation taken to be consisted of slip on 5 slip systems. Using the proposed model which is called combined Hill-Taylor model, compression test of specimens with different number of grains are simulated and the state of strain in each grain and the condition for elimination of size effect in the final geometry of specimen is studied. The results suggest that the state of strain in each grain is individual and depends on the orientation of that gain which changes abruptly by passing through the grain boundaries. It is also observed that as the number of grains increases, the final geometry approaches to the expected ideal geometry. This trend is studied in statistical point of view and it became clear that as the number of grains increases the average of the state of strain approaches the ideal condition while the scatter in the state of strain in grains continue to maintain. Manuscript profile