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Satyam Suwas - One of the best experts on this subject based on the ideXlab platform.
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effect of phase contiguity and morphology on the evolution of Deformation Texture in two phase alloys
Metallurgical and Materials Transactions A-physical Metallurgy and Materials Science, 2017Co-Authors: N P Gurao, Satyam SuwasAbstract:Deformation Texture evolution in two-phase xFe-yNi-(100-x-y)Cr model alloys and Ti-13Nb-13Zr alloy was studied during rolling to develop an understanding of micro-mechanisms of Deformation in industrially relevant two-phase FCC-BCC steels and HCP-BCC titanium alloys, respectively. It was found that volume fraction and contiguity of phases lead to systematic changes in Texture, while morphology affects the strength of Texture. There was a characteristic change in Texture from typical Brass-type to a weaker Copper-type Texture in the austenite phase accompanied with a change from alpha fiber to gamma fiber in ferrite phase for Fe-Ni-Cr alloys with increase in fraction of harder ferrite phase. However, similar characteristic Texture evolution was noted in both alpha and beta phase irrespective of the different initial morphologies in Ti-13Nb-13Zr alloy. Viscoplastic self-consistent simulations with two-phase scheme were able to qualitatively predict Texture evolution in individual phases. It is proposed that the transition from iso-strain-type behavior for equiaxed microstructure at low strain to iso-stress-type behavior at higher strain is aided by the presence of higher volume fraction of the second phase and increasing aspect ratio of individual phases in two-phase alloys.
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new insights into the development of microstructure and Deformation Texture in nickel 60 wt cobalt alloy
Acta Materialia, 2014Co-Authors: R Madhavan, R K Ray, Satyam SuwasAbstract:The present study investigates the critical role of Deformation twinning and Bs-type shear bands in the evolution of Deformation Texture in a low stacking fault energy Ni-60Co alloy up to very large rolling strain (epsilon(t) approximate to 4). The alloy develops a strong brass-type rolling Texture, and its formation is initiated at the early stages of Deformation. Extensive twinning is observed at the intermediate stages of Deformation, which causes significant Texture reorientation towards alpha-fiber. A pseudo-in-situ electron back-scattered diffraction technique adopted to capture orientation changes within individual grains during the early stages suggests that twinning should be subsequently aided by crystallographic slip to attain alpha-fiber ( parallel to ND) orientations. Beyond 40% reduction, Deformation is dominated by Bs-type shear bands, and the banding coincides with the evolution of parallel to ND components. The volume fraction of shear bands is significant at higher strains, and crystallites within the bands preferentially show parallel to ND components. The absence of the Cu {1 1 2} component in the initial Texture, and subsequently during rolling, indicates that, for the evolution of a brass-type Texture, the presence of the Cu component is not a necessary condition. The final rolling Texture is a synergistic effect of Deformation twinning and shear banding. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
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microstructure and Texture evolution during accumulative roll bonding of aluminium alloys aa2219 aa5086 composite laminates
Journal of Materials Science, 2012Co-Authors: Shibayan Roy, Satyam Suwas, B R Nataraj, S Kumar, K ChattopadhyayAbstract:Accumulative roll bonding of two aluminium alloys, AA2219 and AA5086 was carried out up to 8 passes. During the course of ARB, the Deformation inhomogeneity between the two alloy layers results in interfacial instability after the 4th pass, necking of the AA5086 layers after the 6th pass and fracture along the necked regions after the 7th and 8th pass. The EBSD analysis shows Deformation bands along the interfaces after 8 passes of ARB. The ARB-processed materials predominantly show characteristic Deformation Texture components. The weak Texture after the 2nd pass results from the combination of a weakly-Textured starting AA2219 layer and a strongly-Textured starting AA5086 layer. A strong Deformation Texture forms due to the high imposed strain after a higher number of ARB passes. Subgrain formation and related shear banding induces copper/S components in the case of the small elongated grains, while planar slip leads to the formation of brass component in the large elongated grains.
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Texture and microstructural evolution in pearlitic steel during triaxial compression
Metallurgical and Materials Transactions A-physical Metallurgy and Materials Science, 2012Co-Authors: Pankaj Kumar, N P Gurao, Arunansu Haldar, Satyam SuwasAbstract:This article presents the Deformation behavior of high-strength pearlitic steel deformed by triaxial compression to achieve ultra-fine ferrite grain size with fragmented cementite. The consequent evolution of microstructure and Texture has been studied using scanning electron microscopy, electron back-scatter diffraction, and X-ray diffraction. The synergistic effect of diffusion and Deformation leads to the uniform dissolution of cementite at higher temperature. At lower temperature, significant grain refinement of ferrite phase occurs by Deformation and exhibits a characteristic Deformation Texture. In contrast, the high-temperature deformed sample shows a weaker Texture with cube component for the ferrite phase, indicating the occurrence of recrystallization. The different mechanisms responsible for the refinement of ferrite as well as the fragmentation of cementite and their interaction with each other have been analyzed. Viscoplastic self-consistent simulation was employed to understand Deformation Texture in the ferrite phase during triaxial compression.
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analysis of Texture evolution in pure magnesium and the magnesium alloy am30 during rod and tube extrusion
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2011Co-Authors: Somjeet Biswas, Satyam Suwas, Rajiv Sikand, Anil K GuptaAbstract:The evolution of microstructure and Texture during extrusion of pure magnesium and its single phase alloy AM30 has been studied experimentally as well as by crystal plasticity simulation. Microstructure and micro-Texture were characterized by electron back scattered diffraction (EBSD), bulk-Texture was measured using X-ray diffraction and Deformation Texture simulations were carried out using visco-plastic self consistent (VPSC) model. In spite of clear indications of the occurrence of dynamic recrystallization (DRX), simulations were able to reproduce the experimental Textures successfully. This was attributed to the fact that the Textures were c-type fibers with their axis of rotation parallel to the c-axis and DRX leads to simply rotate the Texture around the c-axis.
J A Szpunar - One of the best experts on this subject based on the ideXlab platform.
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fabrication and characterization of al al2o3 zrc composite produced by accumulative roll bonding arb process
Journal of Alloys and Compounds, 2015Co-Authors: M Shamanian, Mahyar Mohammadnezhad, Hamed Asgari, J A SzpunarAbstract:Abstract In this study, accumulative roll bonding process was used to manufacture a high-strength aluminum matrix composite dispersed with anodized alumina and zirconium carbide particles. Furthermore, the microstructure evolution, mechanical properties and Deformation Texture of the composite samples are reported. The results illustrated that when the number of cycles was increased, the distribution of reinforcement particles in the aluminum matrix improved, and the particles became finer. During process, it was observed that as the strain increased with the number of cycles, the tensile strength, microhardness and elongation of produced composites increased as well. The comparison Texture results after various rolling cycles indicated that the overall Texture intensity increases and a wholly-different-strong Texture develop. The main textural component is the Rotated Cube component.
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evolution of Deformation and annealing Textures in incoloy 800h ht via different rolling paths and strains
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2014Co-Authors: Hamed Akhiani, Majid Nezakat, J A SzpunarAbstract:Abstract In this report, we characterize the Deformation and annealing Textures of Incoloy 800H/HT, following different rolling conditions that produced different Textures in this material. Incoloy 800H/HT is an austenitic Fe–Ni super alloy and is considered to be a candidate material for Gen IV nuclear reactors. Fossil fuel plants have used this alloy for decades; however, as grain structure and Texture parameters can strongly affect its physical and mechanical properties in-service, engineers should consider some structural modifications before using this alloy in nuclear reactors. In this study, we used Thermo-Mechanical Processing (TMP) to alter the Texture of Incoloy 800H/HT. We applied various thickness reductions (10%, 30%, 50%, 70%, and 90%) to this alloy using two different rolling paths, followed by annealing. Our detailed study of the Deformation and annealing Texture evolution shows that upon different rolling paths, the final Deformation Texture and the annealing Texture were different. Brass Texture was the dominant component for the uni-directional rolled (UDR) samples, while a combination of brass (B) and ND-rotated brass (BT) were the dominant components in the cross-rolled (CR) samples. Annealing Textures of UDR samples were mainly Goss, copper, S, recrystallized brass ( { 236 } 〈 385 〉 ) and minor copper twin { 552 } 〈 115 〉 components. At lower Deformations ( { 236 } 〈 385 〉 ) and minor Goss twin ( 113 ) 〈 33 ¯ 2 〉 . However, at higher rolling reductions, the B+BT Deformation Texture was retained for the CR samples.
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effect of arb process on textural evolution of aa1100 aluminum alloy
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2010Co-Authors: Mohammad Raei, Mohammad Reza Toroghinejad, Roohollah Jamaati, J A SzpunarAbstract:Abstract In the present work, commercial purity aluminum strips were highly strained up to an equivalent strain of 4.8 by the accumulative roll bonding (ARB) process at ambient temperature. Furthermore, the influence of the ARB process on the development of Deformation Texture at the quarter thickness of ARB-processed samples was considered. ARB process leads to the formation of strong orientation along the β-fiber and also to pronounced Dillamore and Copper components. It was found that Textures which were formed at ARB-processed samples were almost the same for various ARB cycles and only their intensities differ. Also, the fraction of grains with sharp high angle boundaries increased when the number of ARB cycles increased.
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determination of active slip twinning modes in az31 mg alloy near room temperature
Journal of Materials Engineering and Performance, 2007Co-Authors: Emilie Hsu, J A Szpunar, Ravi Verma, Jon T CarterAbstract:In order to determine the Deformation modes in AZ31 magnesium alloy at room temperature, computer simulations of Deformation Texture development and calculation of formability have been carried out. The simulation results were compared with the measured Texture results. Based on agreement between the experiments and simulations the active Deformation modes were determined. A Visco Plastic Self Consistent model was employed for the simulation of plastic Deformation. Simulations and experiments were performed for different initial Textures. The goal of the study was to develop the understanding of Deformation Texture evolution and its effects on mechanical properties of magnesium, with an ultimate goal of improving room temperature formability of magnesium alloys.
Ehsan Borhani - One of the best experts on this subject based on the ideXlab platform.
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nano ultrafine grained aa2024 alloy processed by accumulative roll bonding a study of microstructure Deformation Texture and mechanical properties
Journal of Alloys and Compounds, 2017Co-Authors: M Alvand, M Naseri, Ehsan Borhani, Hassan AbdollahpourAbstract:Abstract In this study, the effect of accumulative roll bonding (ARB) process on the microstructure, Deformation Texture and mechanical properties of AA2024 strip was investigated. Microstructural observations were done by electron backscattering diffraction (EBSD) technique and scanning electron microscopy (SEM). Also, mechanical properties were performed by uniaxial tensile and microhardness tests. It was observed that accumulative roll bonding is a promising process for production of nano/ultrafine grained (NG/UFG) 2024 aluminum alloy after seventh ARB cycles, reaching grain sizes of smaller than 120 nm. The fraction of high angle grain boundaries and mean misorientation were represented increased by increasing the strain during the ARB process and reached to a saturated value of 64% and 25.37°, respectively. Deformation Texture evolution demonstrated that the formation of nano shear bands at the final ARB cycle was facilitated by the formation of Brass {011}〈211〉 and Goss {011}〈100〉 components. By increasing the number of ARB cycles, the yield strength, tensile strength and microhardness of the ARB processed sample improved and reached to 345 MPa, 450 MPa and 141 HV after 7 cycles, respectively, which were 2.65, 2.40 and 2.23 times higher than obtained values for initial materials, i.e. 130 MPa, 188 MPa and 63.5 HV. After the tensile test, debonding can be observed especially in the interface formed in the last cycle. Observations revealed that the failure mode in the accumulatively roll bonded AA2024 strip was a shear ductile rupture with elongated shallow shear dimples.
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effect of strain path on microstructure Deformation Texture and mechanical properties of nano ultrafine grained aa1050 processed by accumulative roll bonding arb
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2016Co-Authors: M Naseri, M Reihanian, Ehsan BorhaniAbstract:Abstract Commercial pure Al sheets were severe plastically deformed at room temperature by accumulative roll bonding (ARB) and cross accumulative roll bonding (CARB). Change in strain path was imposed during CARB by rotating the sheets with 90° around the normal direction axis between each cycle. Microstructural evolution of processed sheets was studied by electron back scattered diffraction (EBSD) analysis and revealed that nano/ultrafine grains (NG/UFG) with the average grain size of 380 nm and 155 nm were formed by both processing routes after eight cycles, respectively. The fraction of high angle grain boundaries and mean misorientation angle of the boundaries in the CARB were 49% and 40.20°, respectively, in comparison to that of ARB sample (41% and 37.37°). Deformation Texture evolution demonstrated that the change in strain path leads to the formation of strong orientation along the β-fiber. The major Texture components for ARB specimens were Brass {011} and S {123} while those for CARB were Brass {011} and Goss {011} . The CARB processed specimen exhibited the tensile strength, microhardness and elongation of about 230 MPa, 92 HV and 13% compared with ARB sample (180 MPa, 80 HV and 10.5%) after eight cycles. Scanning electron microscopy (SEM) observations of tensile fracture surface of specimens revealed ductile type fracture.
Yi Chen - One of the best experts on this subject based on the ideXlab platform.
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Texture evolution and dynamic recrystallization in a beta titanium alloy during hot rolling process
Journal of Alloys and Compounds, 2015Co-Authors: Hongchao Kou, Yi Chen, Bin Tang, Xiangyi Xue, Yuwen CuiAbstract:Abstract Crystallographic Texture evolution in a β-Titanium alloy (Ti–15Mo–3Al–2.7Nb–0.2Si) during hot-rolling process is investigated. The results reveal that the shear strain in the surface area leads to weakening of Texture intensity, that in turn gives rise to formation of significant through-thickness Texture gradients. It is observed that the dynamic recrystallization (DRX), during the hot-rolling, occurs and is accompanied with the other weakening of Deformation Texture. The mechanism of the formation and evolution of the DRX grains, revealed by EBSD analysis, suggests that the weakening of the Texture is associated with the rotation of the DRX grains towards the preferred slip systems having large misorientations between themselves.
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an experimental study on the mechanism of Texture evolution during hot rolling process in a β titanium alloy
Journal of Alloys and Compounds, 2014Co-Authors: Hongchao Kou, Yi Chen, Bin Tang, Yuwen Cui, Feng Sun, Xiangyi XueAbstract:Abstract The formation of crystallographic Texture in a β-titanium alloy (Ti–15Mo–3Al–2.7Nb–0.2Si, wt.%) during the dynamic recrystallization (DRX) in hot rolling process was studied. The results reveal that the DRX occurs during the hot rolling process, which in turn results in the weakening of the Deformation Texture. The EBSD and TEM analyses further confirm that the weakening is associated with the randomly-distributed orientation relations of newly formed DRX grains, as well as the large misorientation remained between the deformed matrix and the DRX grains.
Mohammad Reza Toroghinejad - One of the best experts on this subject based on the ideXlab platform.
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effect of stacking fault energy on Deformation Texture development of nanostructured materials produced by the arb process
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2014Co-Authors: Roohollah Jamaati, Mohammad Reza ToroghinejadAbstract:Abstract In this study, the effect of stacking fault energy on Deformation Texture development of nanostructured face-centered cubic (FCC) materials fabricated via accumulative roll bonding (ARB) process was investigated. Textural evolution was evaluated using X-ray diffraction and microstructural observation was evaluated by transmission electron microscopy (TEM). It was found that in the copper and brass sample, unlike the aluminum sample, the intensity of Brass component remarkably increased at the high Deformation, resulting from the slip of dislocations, mechanical twinning, and even shear banding. The main difference between aluminum (representing the high SFE), copper (representing the medium SFE) and the brass (representing the low SFE) Textures lied in the prominence of the Copper component in the aluminum (at all cycles) and copper (at low and high cycles) Texture and the absence of this component in the brass (at all cycles) and copper (at medium cycles) Texture. In fact, as the SFE decreased, the Copper component replaced by a Brass orientation. Also it was realized that the SFE plays a decisive role in the occurrence of Texture transition of FCC materials. On one hand, the continuous recrystallization occurred in the aluminum sample and this phenomenon led to decrease in the orientation intensities of β-fiber. On the other hand, the discontinuous recrystallization occurred in the copper and brass sample and this phenomenon led to decrease in the orientation intensities of β-fiber, Copper, and Dillamore Textures. In fact, as the SFE decreased, the stacking faults became wider, making cross-slip more difficult. Hence, mechanical twinning was favored. Therefore, the possible restoration mechanism in the copper and brass was discontinuous recrystallization.
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effect of alloy composition stacking fault energy second phase particles initial thickness and measurement position on Deformation Texture development of nanostructured fcc materials fabricated via accumulative roll bonding process
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2014Co-Authors: Roohollah Jamaati, Mohammad Reza ToroghinejadAbstract:Abstract In the present work, the effective parameters on Deformation Texture development of nanostructured face-centered cubic (FCC) materials fabricated via accumulative roll bonding (ARB) process were investigated. Textural evolution was evaluated using X-ray diffraction and microstructural observation was evaluated by transmission and scanning electron microscopy. It was found that the extensive continuous recrystallization was occurred at fourth cycle (for AA1100 alloy) and sixth cycle (for AA5083 alloy) and this phenomenon led to decrease in the orientation intensities of β-fiber. The major characteristic difference between the aluminum (representing the high stacking fault energy (SFE)) and the brass (representing the low SFE) Textures lied in the prominence of the Copper component in the aluminum Texture and the absence of this component in the brass Texture. The results also revealed that the discontinuous recrystallization was occurred in the brass sample at all cycles and this phenomenon led to decrease in the orientation intensities of β-fiber, Copper, and Dillamore Textures. The intensity of Texture was very weak in the composites than in the pure aluminum due to the formation of a Deformation zone near large second phase particles and also occurrence of particle stimulated nucleation (PSN) during ARB process. There was a Texture transition from rolling Textures to Rotated Cube component in both aluminum strip and foil samples. But, the Texture transition in the aluminum foil occurred sooner than in the aluminum strip. The Texture near the quarter thickness showed a typical rolling Texture, and the Texture near the surface presented a shear one. Due to the effect of friction between the roll and the sample contact surface, the Texture evolution at the surface layer was different from that at the quarter thickness layer.
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effect of arb process on textural evolution of aa1100 aluminum alloy
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2010Co-Authors: Mohammad Raei, Mohammad Reza Toroghinejad, Roohollah Jamaati, J A SzpunarAbstract:Abstract In the present work, commercial purity aluminum strips were highly strained up to an equivalent strain of 4.8 by the accumulative roll bonding (ARB) process at ambient temperature. Furthermore, the influence of the ARB process on the development of Deformation Texture at the quarter thickness of ARB-processed samples was considered. ARB process leads to the formation of strong orientation along the β-fiber and also to pronounced Dillamore and Copper components. It was found that Textures which were formed at ARB-processed samples were almost the same for various ARB cycles and only their intensities differ. Also, the fraction of grains with sharp high angle boundaries increased when the number of ARB cycles increased.