Abstract
The paper examines the tensile deformation behavior of the Al-Mg-Si alloy (6061 Al alloy) subjected to various aging conditions. 6061 Al alloy is commonly used in aerospace/aircraft industry due to its performance on corrosion resistance, formability, and weldability. Five different heat treatment procedures, including T4 natural aging and T6 peak-strength temper conditions, were designed to investigate the effect of artificial aging on the mechanical behavior of the alloy. Tensile tests were performed to determine the stress–strain behavior of the material both in uniform and non-uniform deformation regions. Mechanical material properties including yield, ultimate and fracture strengths, uniform and total strains, hardness, strength coefficient, and strain-hardening exponent were obtained experimentally. The relationship between equivalent strain, equivalent stress, and hardness is also examined. The fracture strength of specimens was determined to be less than the Holloman model predictions for the fracture strains of specimens. Void development, which is dependent on the amount of plastic strain development, is determined to be the main reason for this discrepancy between the Holloman model and fracture stress. To calculate the homogeneous stress in the metal matrix of the porous domain, Eshelby-based Mori–Tanaka method (MTM) was used. The calculated average stress in the metal matrix shows good agreement with the Holloman equation predictions. Thus, void development explains the interrupted strain hardening after necking.
Similar content being viewed by others
References
W.S. Miller, L. Zhuang, J. Bottema, A.J. Wittebrood, P. De Smet, A. Haszler, and A. Vieregge, Recent Development in Aluminium Alloys for the Automotive Industry, Mater. Sci. Eng., A, 2000, 280(1), p 37–49
D.S.M. George and E. Totten, Handbook of Aluminum, Marcel Dekker, New York, NY, 2003
J.C. Benedyk, 3—Aluminum Alloys for Lightweight Automotive Structures, Mater. Des. Manuf. Lightweight Veh., 2010, https://doi.org/10.1533/9781845697822.1.79
J. Buha, R.N. Lumley, and A.G. Crosky, Microstructural Development and Mechanical Properties of Interrupted Aged Al-Mg-Si-Cu Alloy, Metall. Mater. Trans. A, 2006, 37(10), p 3119–3130
Z. Chen, G. Fang, and J.Q. Zhao, Formability Evaluation of Aluminum Alloy 6061-T6 Sheet at Room and Elevated Temperatures, J. Mater. Eng. Perform., 2017, 26(9), p 4626–4637
R. Braun, On the Stress Corrosion Cracking Behaviour of 6XXX Series Aluminium Alloys, Int. J. Mater. Res., 2010, 101(5), p 657–668
C. ASM Handbook Committe, ASM Metals Handbook Volume 4, 10th ed., ASM International, Cleveland, OH, 1991
C.D. Marioara, H. Nordmark, S.J. Andersen, and R. Holmestad, Post-β″ Phases and Their Influence on Microstructure and Hardness in 6xxx Al-Mg-Si Alloys, J. Mater. Sci., 2006, 41(2), p 471–478
R.S. Yassar, D.P. Field, and H. Weiland, Transmission Electron Microscopy and Differential Scanning Calorimetry Studies on the Precipitation Sequence in an Al-Mg-Si Alloy: AA6022, J. Mater. Res., 2005, 20(10), p 2705–2711
S. Pogatscher, H. Antrekowitsch, T. Ebner, and P.J. Uggowitzer, The Role of Co-Clusters in the Artificial Aging of AA6061 and AA6060, Light Metals, C.E. Suarez, Ed., Springer, Cham, 2012, p 415–420
I. Dutta and S.M. Allen, A Calorimetric Study of Precipitation in Aluminum Alloy 6061, J. Mater. Sci. Lett., 1991, 10, p 323–326. https://doi.org/10.1007/BF00719697
G.A. Edwards, K. Stiller, G.L. Dunlop, and M.J. Couper, The Precipitation Sequence in Al-Mg-Si Alloys, Acta Mater., 1998, 46(11), p 3893–3904
J. Buha, R.N. Lumley, A.G. Crosky, and K. Hono, Secondary Precipitation in an Al-Mg-Si-Cu Alloy, Acta Mater., 2007, 55(9), p 3015–3024
V. Massardier, T. Epicier, and P. Merle, Correlation between the Microstructural Evolution of A 6061 Aluminium Alloy and the Evolution of Its Thermoelectric Power, Acta Mater., 2000, 48(11), p 2911–2924
D. Maisonnette, M. Suery, D. Nelias, P. Chaudet, and T. Epicier, Effects of Heat Treatments on the Microstructure and Mechanical Properties of a 6061 Aluminium Alloy, Mater. Sci. Eng., A, 2011, 528(6), p 2718–2724. https://doi.org/10.1016/j.msea.2010.12.011
F. Ozturk, A. Sisman, S. Toros, S. Kilic, and R.C. Picu, Influence of Aging Treatment on Mechanical Properties of 6061 Aluminum Alloy, Mater. Des., 2010, 31(2), p 972–975. https://doi.org/10.1016/j.matdes.2009.08.017
C. Xu, H. He, W. Yu, and L. Li, Influence of Quenching Temperature on Peak Aging Time and Hardness of Al-Mg-Si-Cu Alloys Strengthened by Nano-Sized Precipitates, Mater. Sci. Eng., A, August 2019, 744(2018), p 28–35. https://doi.org/10.1016/j.msea.2018.11.149
T. Petit, J. Besson, C. Ritter, K. Colas, L. Helfen, and T.F. Morgeneyer, Effect of Hardening on Toughness Captured by Stress-Based Damage Nucleation in 6061 Aluminum Alloy, Acta Mater., 2019, 180, p 349–365. https://doi.org/10.1016/j.actamat.2019.08.055
B.S. Aakash, J.P. Connors, and M.D. Shields, Variability in the Thermo-Mechanical Behavior of Structural Aluminum, Thin-Walled Struct., 2019, 144(January), p 106122. https://doi.org/10.1016/j.tws.2019.01.053
Y. Zhu and M.D. Engelhardt, Prediction of Ductile Fracture for Metal Alloys Using a Shear Modified Void Growth Model, Eng. Fract. Mech., 2018, 190, p 491–513. https://doi.org/10.1016/j.engfracmech.2017.12.042
J. Banhart, C.S.T. Chang, Z. Liang, N. Wanderka, M.D.H. Lay, and A.J. Hill, Natural Aging in Al-Mg-Si Alloys—A Process of Unexpected Complexity, Adv. Eng. Mater., 2010, 12(7), p 559–571
ASTM, Standard Test Methods for Tension Testing of Metallic Materials, ASTM, West Conshohocken, PA, 2009, https://doi.org/10.1520/e0008
ASTM, ASTM E384-11. Standard Test Method for Knoop and Vickers Hardness of Materials, 2011, p 43
S.J. Andersen, H.W. Zandbergen, J. Jansen, C. TrÆholt, U. Tundal, and O. Reiso, The Crystal Structure of the Β″ Phase in Al-Mg-Si Alloys, Acta Mater., 1998, 46(9), p 3283–3298
ASTM Standard, B209M-14: Standard Specification for Aluminum and Aluminum Alloy Sheet and Plate, ASTM Int., 2014, (November), p 1–26.
K.K. Saxena, K. Drotleff, and J. Mukhopadhyay, Elevated Temperature Forming Limit Strain Diagrams of Automotive Alloys Al6014-T4 and DP600: A Case Study, J. Strain Anal. Eng. Des., 2016, 51(6), p 459–470. https://doi.org/10.1177/0309324716651028
T. Altan, S.-I. Oh, and H. Gegel, Metal Forming, 7th ed., American Society for Metals, Cleveland, OH, 2000
S. Wang, Z. Chen, and C. Dong, Tearing Failure of Ultra-Thin Sheet-Metal Involving Size Effect in Blanking Process: Analysis Based on Modified GTN Model, Int. J. Mech. Sci., 2017, 133(April), p 288–302. https://doi.org/10.1016/j.ijmecsci.2017.08.028
A.O. Adesola, A.G. Odeshi, and U.D. Lanke, The Effects of Aging Treatment and Strain Rates on Damage Evolution in AA 6061 Aluminum Alloy in Compression, Mater. Des., 2013, 45, p 212–221. https://doi.org/10.1016/j.matdes.2012.08.021
P. Zhang, S.X. Li, and Z.F. Zhang, General Relationship between Strength and Hardness, Mater. Sci. Eng., A, 2011, 529(1), p 62–73
J.M. Choung and S.R. Cho, Study on True Stress Correction from Tensile Tests, J. Mech. Sci. Technol., 2008, 22(6), p 1039–1051
W. Hosford and R. Caddell, Metal Forming, 3rd ed., Cambridge University Press, Cambridge, 2007
H. Agarwal, A.M. Gokhale, S. Graham, and M.F. Horstemeyer, Void Growth in 6061-Aluminum Alloy Under Triaxial Stress State, Mater. Sci. Eng., A, 2003, 341(1-2), p 35–42
J.D. Eshelby, The Determination of the Elastic Field of an Ellipsoidal Inclusion, and Related Problems, Proc. R. Soc. Lond. Ser. A. Math. Phys. Sci., 1957, 241(1226), p 376–396. https://doi.org/10.1098/rspa.1957.0133
T. Mori and K. Tanaka, Average Stress in Matrix and Average Elastic Energy of Materials with Misfitting Inclusions, Acta Metall., 1973, 21(5), p 571–574. https://doi.org/10.1016/0001-6160(73)90064-3
Acknowledgments
Funding: This study was funded by Istanbul Technical University (BAP Project No. 38489).
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they have no conflict of interest.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Yildiz, R.A., Yilmaz, S. Stress–Strain Properties of Artificially Aged 6061 Al Alloy: Experiments and Modeling. J. of Materi Eng and Perform 29, 5764–5775 (2020). https://doi.org/10.1007/s11665-020-05080-6
Received:
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11665-020-05080-6