Papers by Keyword: AA5083 Aluminum Alloy

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Authors: Xue Feng Xu, Ning Li, Gao Chao Wang, Hong Bo Dong
Abstract: A thermal-mechanical coupled analysis of superplastic differential temperature deep drawing (SDTDD) with the MARC finite element code is performed in this paper. Initial drawing blank of an AA5083 bracket was calculated and adjusted according to the simulation result. During the SDTDD simulation, the power-law constitutive model of AA5083 was established as function of temperature and implanted in software MARC through new complied subroutine. Under the guide of the numerical simulation, the die was fabricated and the AA5083 bracket was successfully manufactured via superplastic differential temperature deep drawing. In forming practice, the temperature of female die was kept at 525°C, i.e. the optimal superplastic temperature of AA5083, and the punch was cooled by the flowing water throughout the forming process. The drawing velocity of punch was 0.1mm/s. Results revealed that the formed bracket had a sound uniform thickness distribution. Good agreement was obtained between the formed thickness profiles and the predicted ones.
Authors: H. Takahara, Y. Motoyama, Masato Tsujikawa, Sachio Oki, Sung Wook Chung, Kenji Higashi
Authors: H. Ahmed, Mary A. Wells, Daan M. Maijer, Menno van der Winden
Abstract: A mathematical model has been developed and validated to predict deformation, temperature and microstructure evolution during multi-pass hot rolling of an AA5083 aluminum alloy. The validated model was employed to examine the effect of changing the number of rolling passes and the strain partitioning during multi-pass rolling on the material stored energy and the resulting microstructure. Results indicate that the number of rolling passes has a significant effect on the material stored energy. In addition, the way the strain is partitioned in two-pass rolling cases affects the material stored energy with decreasing strain/pass providing the highest stored energy in the material after rolling and vice versa. The reason behind these results was further investigated indicating that the thermal evolution during rolling may significantly influence the material stored energy and subsequent recrystallization kinetics.
Authors: Shinya Kamimura, Koichi Kitazono, Eiichi Sato, Kazuhiko Kuribayashi
Abstract: A new application of superplasticity was proposed in the manufacturing process of metal foams. Preform sheets were manufactured using superplastic 5083 aluminum alloy sheets through accumulative roll-bonding (ARB) process. Microcellular aluminum foam plates with 50% porosity were produced through solid-state foaming under the superplastic condition. The cell shape was oblate spheroid, which is effective to reduce the thermal conductivity. The present aluminum foam plates have a potential as an excellent heat insulator.
Authors: Bin Hao, Ji Shan Zhang, Da Cheng Liu
Abstract: In the present investigation, the composite powder with 20wt.% particulate B4C and 80wt.% nanocrystalline 5083 Al was fabricated using mechanically milling at cryogenic temperature (cryomilling). After this, the cryomilled composite powder was homogeneously blended with an equal amount of unmilled coarse-grained 5083 Al. The blended powder was consolidated with hot-pressing at 500°C, followed by hot extrusion at 410°C. The consolidated composite consists of 10wt.% B4C, 50wt.% coarse grain 5083 Al and the balance nanocrystalline 5083 Al. The microstructure evolution of the composite during cryomilling and consolidation was investigated by X-ray diffraction (XRD), optical microscopy (OM) and scanning electron microscopy (SEM). The results show that the particle size of the cryomilled composite powder became smaller and then bigger with milling time longer. This demonstrates the course rely mainly on broken first, and then rely mainly on cold welding with milling time longer. B4C particles can be distributed in 5083 Al matrix uniformly. In addition, the presence of oxygen and nitrogen in cryomilled powders has been demonstrated in this paper.
Authors: Yu Hwang Yu, Shyong Lee, Bin-Lung Ou
Authors: Terry McNelley, Keiichiro Oh Ishi, Srinivasan Swaminathan, John Bradley, Paul Krajewski, Eric M. Taleff
Abstract: Thermomechanical processing to enable superplasticity in AA5083 materials includes cold working followed by heating prior to hot blow forming. Upon heating for forming at 450°C, a B-type ({110}) rolling texture is replaced by a near-random texture with a weak superimposed cube orientation parallel to the sheet normal. The presence of refined grains 7 – 8μm in size reflects the predominance of particle-stimulated nucleation of recrystallization prior to forming. The subsequent evolution of microstructure, texture and cavitation behaviour during biaxial deformation in the solute drag creep (SDC) and grain boundary sliding (GBS) regimes will be presented.
Authors: X.F. Xu, L.M. Tang, G.Q. Tong
Abstract: A comparative study of different element formulations in simulating superplastic forming with the MARC finite element code is performed in the paper. Simulations were accomplished with solid, shell, membrane elements to predict forming characteristics and pressure-time curves. Finite element analysis (FEA) predictions of SPF pressure-time curves were found to be greatly affected by the element type and the strain rate control algorithms. Two strain rate control algorithms were applied in the present study: an algorithm based on limiting the rate of deformation with the average strain rate of all the elements, i.e. the build-in method in MARC, and a second algorithm which limits the rate of deformation based on the average strain rate of the elements with the 20 highest strain rates. The resulting pressure-time curves for each of these formulations were compared with respect to each type of element. Under the guide of the analysis, the die was fabricated and the AA5083 bracket was successfully manufactured. Good agreement was obtained between predicted and measured thickness in the part.
Authors: Toshiya Shibayanagi, Masaaki Naka
Abstract: The present paper deals with the control of microstructure of friction stir processed aluminum alloys focusing on grain refinement, thermal stability at elevated temperature and texture development in some aluminum alloys such as 5083, 6061 and 7075 commercial aluminum alloys. 3mm thickness plates of 5083, 6061 and 7075 Al alloys were friction stir processed/welded with several rotation speeds and travelling speeds. Optical microscopy revealed the grain refinement in the stirred zone of each alloy and the average grain size decreased with decreasing rotation speed under various travelling speeds. Annealing of the joints brought about abnormal grain growth at temperatures higher than 773K for 5083 alloy. Critical temperature of the abnormal grain growth tended to decrease as the rotation speed decreased for the fixed travelling speed. Dissimilar joining of 5083 Al alloy to 6061 Al alloy also showed abnormal grain growth when annealed at 773K. A peculiar texture development of 7075 Al joint showing (111)//ND-oriented grains existing throughout the nugget was revealed by EBSP analysis.
Authors: P.D. Pitcher, C.M. Styles
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