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Experimental formability evaluation for aluminium alloy sheets under hot stamping conditions
ZHANG Ruiqiang, LI Jiaqi, SHI Zhusheng, LIN Jianguo
download PDFAbstract. The process of Hot Form and Quench for aluminium alloys, known as HFQ®, has been developed and applied to manufacture lightweight, high-strength engineering panel components in the automotive industry. However, formability evaluation for the alloys under hot stamping conditions is challenging. In this study, a recently developed biaxial testing method has been applied to aluminium alloy AA6082 for formability evaluation at temperatures ranging from 440–510 °C and at a strain rate of 0.1 s-1. This method involves heating cruciform specimens via the resistance heating system in the Gleeble, and deforming them until fracture via a customised biaxial tensile rig which transfers a uniaxial force into biaxial forces. The location for welding thermocouples on cruciform specimen surface for temperature feedback control in the Gleeble is investigated. Furthermore, temperature nonuniformity within the gauge area of cruciform specimens is quantified, and biaxial tensile tests on the specimens are carried out under different conditions. Both the limit strains at the onset of necking and at fracture are determined, and their dependency on the deformation conditions is analysed. It is found that the biaxial testing method is applicable to AA6082 for formability evaluation under hot stamping conditions. In addition, the limit major strains vary with the strain state, but exhibit a minor dependency on the temperature in the range investigated.
Keywords
Aluminium Alloy, Hot Stamping, Formability, Necking, Fracture, Forming Limit Curves
Published online 9/15/2024, 10 pages
Copyright © 2024 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA
Citation: ZHANG Ruiqiang, LI Jiaqi, SHI Zhusheng, LIN Jianguo, Experimental formability evaluation for aluminium alloy sheets under hot stamping conditions, Materials Research Proceedings, Vol. 44, pp 90-99, 2024
DOI: https://doi.org/10.21741/9781644903254-10
The article was published as article 10 of the book Metal Forming 2024
Content from this work may be used under the terms of the Creative Commons Attribution 3.0 license. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
References
[1] J. Lin, T.A. Dean, R.P. Garrett, A.D. Foster, Process for forming metal alloy sheet components, International ‘Patent’ WO 2008059242 A2, (2008), May 22, 2008.
[2] K. Zheng, Y. Dong, J.-H. Zheng, A. Foster, J. Lin, H. Dong, T.A. Dean, The effect of hot form quench (HFQ®) conditions on precipitation and mechanical properties of aluminium alloys, Mater. Sci. Eng. A 761 (2019). https://doi.org/10.1016/j.msea.2019.06.027
[3] ASM Handbook, Heat Treating of Aluminum Alloys, 1991.
[4] Z.W. Xing, J. Bao, Y.Y. Yang, Numerical simulation of hot stamping of quenchable boron steel, Mater. Sci. Eng. A 499 (2009) 28-31. https://doi.org/10.1016/j.msea.2007.09.102
[5] H.S. Liu, Z.W. Xing, J. Bao, B.Y. Song, Investigation of the Hot-Stamping Process for Advanced High-Strength Steel Sheet by Numerical Simulation, J. Mater. Eng. Perform. 19 (2009) 325-334. https://doi.org/10.1007/s11665-009-9510-y
[6] M. Merklein, J. Lechler, Investigation of the thermo-mechanical properties of hot stamping steels, J. Mater. Process. Tech. 177 (2006) 452-455. https://doi.org/10.1016/j.jmatprotec.2006.03.233
[7] B.L. Ma, M. Wan, X.D. Wu, Z.Y. Cai, K.S. Diao, J.Q. Han, Investigation on forming limit of advanced high strength steels (AHSS) under hot stamping conditions, J. Manuf. Process. 30 (2017) 320-327. https://doi.org/10.1016/j.jmapro.2017.10.001
[8] M.S. Mohamed, A.D. Foster, J. Lin, D.S. Balint, T.A. Dean, Investigation of deformation and failure features in hot stamping of AA6082: experimentation and modelling, Int. J. Mach. Tool. Manuf. 53 (2012) 27-38. https://doi.org/10.1016/j.ijmachtools.2011.07.005
[9] S. Bruschi, T. Altan, D. Banabic, P. Bariani, A. Brosius, J. Cao, A. Ghiotti, M. Khraisheh, M. Merklein, A. Tekkaya, Testing and modelling of material behaviour and formability in sheet metal forming, CIRP Annals-Manuf. Tech. 63 (2014) 727-749
[10] S.P. Keeler, Determination of forming limits in automotive stampings, Sheet Met. Ind. 42 (1965) 683-691. https://doi.org/10.4271/650535
[11] G.M. Goodwin, Application of strain analysis to sheet metal forming problems in the press shop, SAE Tech. Pap., 1968, pp. 380-387. https://doi.org/10.4271/680093
[12] S.K. Paul, Controlling factors of forming limit curve: A review, Adv. Industr. Manuf. Eng. 2 (2021). https://doi.org/10.1016/j.aime.2021.100033
[13] A. Atkins, Fracture in forming, J. Mater. Process. Tech. 56 (1996) 609-618. https://doi.org/10.1016/0924-0136(95)01875-1
[14] M. Dilmec, H.S. Halkaci, F. Ozturk, M. Turkoz, Detailed Investigation of Forming Limit Determination Standards for Aluminum Alloys, J. Testing Evaluat. 41 (2013). https://doi.org/10.1520/jte104356
[15] Z. Chen, G. Fang, J.-Q. Zhao, Formability evaluation of aluminum alloy 6061-T6 sheet at room and elevated temperatures, J. Mater. Eng. Perform. 26 (2017) 4626-4637. https://doi.org/10.1007/s11665-017-2895-0
[16] E. Affronti, C. Jaremenko, M. Merklein, A. Maier, Analysis of Forming Limits in Sheet Metal Forming with Pattern Recognition Methods. Part 1: Characterization of Onset of Necking and Expert Evaluation, Materials 11 (2018). https://doi.org/10.3390/ma11091495
[17] P. Bariani, S. Bruschi, A. Ghiotti, A. Turetta, Testing formability in the hot stamping of HSS, CIRP Annals – Manuf. Tech. 57 (2008) 265-268. https://doi.org/10.1016/j.cirp.2008.03.049
[18] L. Ying, T. Gao, H. Rong, X. Han, P. Hu, W. Hou, On the thermal forming limit diagram (TFLD) with GTN mesoscopic damage model for AA7075 aluminum alloy: Numerical and experimental investigation, J. Alloy. Compd. 802 (2019) 675-693. https://doi.org/10.1016/j.jallcom.2019.05.342
[19] H. Rong, P. Hu, L. Ying, W. Hou, J. Zhang, Thermal forming limit diagram (TFLD) of AA7075 aluminum alloy based on a modified continuum damage model: Experimental and theoretical investigations, Int. J. Mech. Sci. 156 (2019) 59-73. https://doi.org/10.1016/j.ijmecsci.2019.03.027
[20] BS EN ISO 12004, Metallic materials — Sheet and strip — Determination of forming-limit curves Part 2: Determination of forminglimit curves in the laboratory, BSI British Standards, 2008. https://doi.org/10.3403/bseniso12004
[21] R. Zhang, Z. Shi, V.A. Yardley, J. Lin, Experimental studies of necking and fracture limits of boron steel sheet under hot stamping conditions, J. Mater. Process. Tech. 302 (2022). https://doi.org/10.1016/j.jmatprotec.2021.117481
[22] R. Zhang, Z. Shi, Z. Shao, T.A. Dean, J. Lin, A novel spatio-temporal method for determining necking and fracture strains of sheet metals, Int. J. Mech. Sci. 189 (2021). https://doi.org/10.1016/j.ijmecsci.2020.105977
[23] R. Zhang, Z. Shi, Z. Shao, V.A. Yardley, J. Lin, An effective method for determining necking and fracture strains of sheet metals, MethodsX 8 (2021). https://doi.org/10.1016/j.mex.2021.101234
[24] R. Zhang, J. Jiang, J. Lin, V.A. Yardley, Investigation of variability in apparent values of materials properties in thermo-mechanical uniaxial tensile tests on sheet metals, J. Manuf. Process. 101 (2023) 737-754. https://doi.org/10.1016/j.jmapro.2023.06.005
[25] R. Zhang, Z. Shao, Z. Shi, T.A. Dean, J. Lin, Effect of cruciform specimen design on strain paths and fracture location in equi-biaxial tension, J. Mater. Process. Tech. 289 (2021). https://doi.org/10.1016/j.jmatprotec.2020.116932
