Abstract
The evolution of microstructure and texture during multipass roller hemming (flanging, pre-hemming and flat hemming) of commercial grade AZ31B-O sheet has been studied using electron backscatter diffraction. The pre-hemming operations were performed with and without local heating using a laser source. It was observed that samples pre-hemmed at room temperature could not be flat hemmed even after applying heat; whereas flat hemming was possible in the sample pre-hemmed with laser heating. The major difference between these samples was the formation of contraction/double twins on the outer radii of the bend in the sample pre-hemmed at room temperature. It is believed that such twins contributed directly or indirectly to the fracture of this sample upon the third pass by leading to the formation of shear bands and/or by significantly hardening the material and not allowing for further deformation.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
B.L. Mordike, and T. Ebert, “Magnesium: Properties −applications — potential,” Materials Science and Engineering A, 302 (1) (2001), 37–45.
A. Galiyev, R. Kaibyshev, and G. Gottstein, “Correlation of plastic deformation and dynamic recrystallization in magnesium alloy ZK60,” Acta Materialia, 49 (7) (2001), 1199–1207.
J.C. Tan and M. J. Tan, “Dynamic Continuous Recrystallization Characteristics in Two Stage Deformation of Mg-3Al-1Zn Alloy Sheet,” Materials Science and Engineering A, 339 (1–2) (2003), 124–32.
Al-Samman, T. and G. Gottstein, “Dynamic recrystallization during high temperature deformation of magnesium,” Materials Science and Engineering: A, 490 (1–2) (2008), 411–420.
J.A. del Valle and O.A. Ruano, “Influence of texture on dynamic recrystallization and deformation mechanisms in rolled or ECAPed AZ31 magnesium alloy,” Materials Science and Engineering: A, 487 (1–2) (2008) 473–480.
S.W. Xu, S. Kamado, N. Matsumoto, T. Honma, Y. Kojima, “Recrystallization mechanism of as-cast AZ91 magnesium alloy during hot compressive deformation,” Materials Science and Engineering: A, 527 (1–2) (2009), 52–60.
J. Carsley and S. Kim, “Warm Hemming of Magnesium Sheet,” Journal of Materials Engineering and Performance, 16 (3) (2007), 331–338.
J.E. Carsley, “Microstructural evolution during bending: Conventional Vs. Roller hemming,” Trends in Materials and Manufacturing Technologies for Transportation Industries, TMS (2005) 169–174.
J.E. Carsley, “Warm Bending Magnesium Sheet for Automotive Closure Panels,” MS&T 2009, Pittsburgh, PA, 25–29 October 2009
X. Li, P. Yang, L.-N. Wang, L. Meng, and F. Cui, “Orientational Analysis of Static Recrystallization at Compression Twins in a Magnesium Alloy AZ31,” Materials Science and Engineering: A, 517 (1–2) (2009), 160–69.
M. Barnett, Z. Keshavarz, A. Beer, and D. Atwell, “Influence of Grain Size on the Compressive Deformation of Wrought Mg-3Al-1Zn,” Acta Materialia, 52 (17) (2004), 5093–103.
M.R. Barnett, “Twinning and the ductility of magnesium alloys: Part II. “Contraction” twins,” Materials Science and Engineering: A, 464 (1–2) (2007), 2007, 8–16.
W.H. Hartt and R. E. Reed-Hill, “Internal Deformation and Fracture of Second-order {10–11}-{10–12} Twins in Magnesium,” Transactions of the Metallurgical Society of AIME, 242 (1968), 1127–133.
M. Knezevic, A. Levinson, R. Harris, R.K. Misrha, R.D. Doherty, S.R. Kalidindi. “Deformation twinning in AZ31: Influence on strain hardening and texture evolution” Acta Materialia, 58 (2010), 6230–6242.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2011 TMS (The Minerals, Metals & Materials Society)
About this chapter
Cite this chapter
Levinson, A., Mishra, R.K., Carsley, J., Doherty, R.D., Kalidindi, S.R. (2011). Microstructure Evolution during Roller Hemming of AZ31B Magnesium Sheet. In: Sillekens, W.H., Agnew, S.R., Neelameggham, N.R., Mathaudhu, S.N. (eds) Magnesium Technology 2011. Springer, Cham. https://doi.org/10.1007/978-3-319-48223-1_72
Download citation
DOI: https://doi.org/10.1007/978-3-319-48223-1_72
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-48568-3
Online ISBN: 978-3-319-48223-1
eBook Packages: Chemistry and Materials ScienceChemistry and Material Science (R0)