The Experts below are selected from a list of 207 Experts worldwide ranked by ideXlab platform
Dietmar Letzig - One of the best experts on this subject based on the ideXlab platform.
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mechanical anisotropy and Deep drawing behaviour of az31 and ze10 magnesium alloy sheets
Acta Materialia, 2010Co-Authors: Sangbong Yi, Jan Bohlen, Frank Heinemann, Dietmar LetzigAbstract:Abstract The influence of the initial microstructure on the Deep Drawability and the associated microstructural evolution in two different magnesium alloy sheets, AZ31 and ZE10, has been examined. Tensile testing at room temperature shows that the AZ31 sheet has high plastic strain ratios, r = 2–3, which are caused by strong basal-type texture. The ZE10 sheet shows lower r values, r ∼ 1, as a result of its weak texture. Deep drawing experiments carried out over the temperature range 100–300 °C revealed that the ZE10 sheet can be successfully Deep-drawn at lower temperatures than the AZ31 sheet. The ZE10 cups show earing despite the weak texture and low normal anisotropy, while earing of the AZ31 cups is negligible. In the ZE10 cups, deformation is accommodated mainly by 〈a〉 slips and by compression as well as secondary twinning. The occurrence of dynamic recrystallization is observed in successfully Deep-drawn AZ31 cups.
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mechanical anisotropy and Deep drawing behaviour of az31 and ze10 magnesium alloy sheets
Acta Materialia, 2010Co-Authors: Ja Ohle, Frank Heinema, Dietmar LetzigAbstract:Abstract The influence of the initial microstructure on the Deep Drawability and the associated microstructural evolution in two different magnesium alloy sheets, AZ31 and ZE10, has been examined. Tensile testing at room temperature shows that the AZ31 sheet has high plastic strain ratios, r = 2–3, which are caused by strong basal-type texture. The ZE10 sheet shows lower r values, r ∼ 1, as a result of its weak texture. Deep drawing experiments carried out over the temperature range 100–300 °C revealed that the ZE10 sheet can be successfully Deep-drawn at lower temperatures than the AZ31 sheet. The ZE10 cups show earing despite the weak texture and low normal anisotropy, while earing of the AZ31 cups is negligible. In the ZE10 cups, deformation is accommodated mainly by 〈a〉 slips and by compression as well as secondary twinning. The occurrence of dynamic recrystallization is observed in successfully Deep-drawn AZ31 cups.
Kenichi Manabe - One of the best experts on this subject based on the ideXlab platform.
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effect of alternating blank holder motion of drawing and wrinkle elimination on Deep Drawability
Journal of Materials Processing Technology, 2007Co-Authors: Tetsuya Yagami, Kenichi Manabe, Y YamauchiAbstract:Abstract The effect of controlling blank holder motion by a newly proposed algorithm on Deep-Drawability was investigated for a circular-cup Deep-drawing process of a thin sheet metal, from the perspective of wrinkle behavior as well as the fracture limit. The algorithm for controlling blank holder motion, such that blank holder force is extremely low, by temporarily allowing wrinkling has been proposed by the authors for improving the Deep-Drawability of thin blanks. Experimental Deep drawing tests of a Cu alloy sheet were carried out to evaluate the effect of motion control on wrinkle behavior. Finite element (FE) simulations of the Deep drawing process were also conducted to investigate the effect of the method on fracture damage reduction. In the previous work by FE simulation, we showed that the motion control method is effective for forming relatively thin sheet blanks, and that the performance of the control method significantly depends on control parameters, i.e., minimum and maximum allowable wrinkle heights, which are associated with wrinkle recognition. The results of the experiment indicated that wrinkle elimination can be successful if wrinkles are within the allowable height range. FE simulation results also indicated that Deep-Drawability can be improved as a result of the reduction of ductile damage accumulation when using blank holder control.
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finite element analysis of magnesium az31 alloy sheet in warm Deep drawing process considering heat transfer effect
Materials Letters, 2006Co-Authors: Abdelwahab Elmorsy, Kenichi ManabeAbstract:This paper reports on the finite element analysis (FEA) of a warm Deep-drawing process. The present investigation of FE analysis of warm Deep-drawing process was initiated with two primary objectives. First, to have first-hand knowledge of warm Deep-drawing process considering heat transfer effect between blank and die components (die and blank holder), second to investigate the improvement of Drawability and temperature distribution of magnesium alloy sheet, AZ31. In this model, both die and blank holder were heated to 300 °C while the punch was kept at room temperature by cooling water. The initial temperature of the blank is the room temperature. The effect of strain rate sensitivity index on the deformation profile was considered in this work. The FE model was performed with two punch speeds to investigate the effect of the punch speed on the temperature distribution. The simulation results were compared to those obtained from the same model without considering heat transfer. In the second model, the die, the blank, the blank holder and the punch were heated to 300 °C. The simulation results revealed that considering heat transfer is very effective for Deep Drawability of Mg alloy. The blank in first model was drawn successfully without any localized thinning and the cup height is higher in contrast to the second model.
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development of a combination punch speed and blank holder fuzzy control system for the Deep drawing process
Journal of Materials Processing Technology, 2002Co-Authors: Kenichi Manabe, Shouichirou Yoshihara, Hiroshi Koyama, Tetsuya YagamiAbstract:Abstract To improve the productivity and formability of sheet metal having strain rate sensitivity, a new control system using a combination punch speed and blank-holder fuzzy control for the Deep-drawing process is proposed. The control algorithm is based on an alternate switch mode system of both blank-holding force (BHF) and punch speed (SPD) control. A newly developed Deep-drawing apparatus with the novel control system achieved on-line simultaneous fuzzy control on both BHF and SPD during the process. The experimental results for a steel sheet show that higher speed Deep drawing can be successful at the SPD over 150 mm/min, at which fracture occurred under constant SPD condition. In addition, it was confirmed that the new combination of SPD and BHF fuzzy control system increased high performance productivity with 25% forming time reduction. Cup wall thickness distribution was also improved and Deep Drawability, beyond that for a constant SPD.
T Masuda - One of the best experts on this subject based on the ideXlab platform.
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improvement of formability in Deep drawing of ultra high strength steel sheets by coating of die
Journal of Materials Processing Technology, 2014Co-Authors: Yohei Abe, Ken-ichiro Mori, Tadahiro Ohmi, T MasudaAbstract:Abstract The formability of Deep drawn ultra-high strength steel sheets in dies coated with either titanium nitride (TiN) or Vanadium carbide (VC) at different drawing speeds and ironing ratios was investigated. TiN was deposited via chemical vapour deposition and physical vapour deposition (PVD) while thermal diffusion was used for VC deposition. In non-coated dies, seizure occurred on both surfaces of the die and the side wall of the drawn cup irrespective of the Deep drawing conditions. The Deep Drawability is improved with coating of die. Whereas in coated dies, seizure became significant only during Deep drawing extreme conditions of 120 mm/s for TiN-coated dies; and this was prevented in VC-coated dies across all drawing conditions. The VC-coated die was suitable for Deep drawing of ultra-high strength steel sheets. The delayed fractured observed in the ultra-high strength steel cups occurred for a large amount of ironing ratio and drawing speeds; and this can be prevented by appropriate heat treatment.
Ken-ichiro Mori - One of the best experts on this subject based on the ideXlab platform.
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Deep Drawability and bendability in hot stamping of ultra high strength steel parts
Key Engineering Materials, 2016Co-Authors: Ken-ichiro Mori, Tomoyoshi Maeno, Yuzo YanagitaAbstract:The Deep Drawability and bendability in hot stamping of ultra-high strength steel parts were examined. Although the cold Drawability is greatly influenced by the blank shape, the limiting drawing depths for the square and circular blanks were equal for hot stamping because of small flow stress. In hot hat-shaped bending using draw-and form-type tools, the effect of the blankholder force generated with the draw-type tools on the springback was small, and the seizure for the form-type tools was smaller than that of the draw-type tools. Since both edges in contact with the electrodes are not heated for resistance heating, cracks were caused at the edges for resistance heating in the transversal directions in hot stamping of an S-rail with form-type tools, and thus it is required to control deformation of the non-heating zones.
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improvement of formability in Deep drawing of ultra high strength steel sheets by coating of die
Journal of Materials Processing Technology, 2014Co-Authors: Yohei Abe, Ken-ichiro Mori, Tadahiro Ohmi, T MasudaAbstract:Abstract The formability of Deep drawn ultra-high strength steel sheets in dies coated with either titanium nitride (TiN) or Vanadium carbide (VC) at different drawing speeds and ironing ratios was investigated. TiN was deposited via chemical vapour deposition and physical vapour deposition (PVD) while thermal diffusion was used for VC deposition. In non-coated dies, seizure occurred on both surfaces of the die and the side wall of the drawn cup irrespective of the Deep drawing conditions. The Deep Drawability is improved with coating of die. Whereas in coated dies, seizure became significant only during Deep drawing extreme conditions of 120 mm/s for TiN-coated dies; and this was prevented in VC-coated dies across all drawing conditions. The VC-coated die was suitable for Deep drawing of ultra-high strength steel sheets. The delayed fractured observed in the ultra-high strength steel cups occurred for a large amount of ironing ratio and drawing speeds; and this can be prevented by appropriate heat treatment.
Yohei Abe - One of the best experts on this subject based on the ideXlab platform.
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improvement of formability in Deep drawing of ultra high strength steel sheets by coating of die
Journal of Materials Processing Technology, 2014Co-Authors: Yohei Abe, Ken-ichiro Mori, Tadahiro Ohmi, T MasudaAbstract:Abstract The formability of Deep drawn ultra-high strength steel sheets in dies coated with either titanium nitride (TiN) or Vanadium carbide (VC) at different drawing speeds and ironing ratios was investigated. TiN was deposited via chemical vapour deposition and physical vapour deposition (PVD) while thermal diffusion was used for VC deposition. In non-coated dies, seizure occurred on both surfaces of the die and the side wall of the drawn cup irrespective of the Deep drawing conditions. The Deep Drawability is improved with coating of die. Whereas in coated dies, seizure became significant only during Deep drawing extreme conditions of 120 mm/s for TiN-coated dies; and this was prevented in VC-coated dies across all drawing conditions. The VC-coated die was suitable for Deep drawing of ultra-high strength steel sheets. The delayed fractured observed in the ultra-high strength steel cups occurred for a large amount of ironing ratio and drawing speeds; and this can be prevented by appropriate heat treatment.
