Modeling the 3D Plastic Anisotropy of a Magnesium Alloy Processed Using Severe Plastic Deformation
The mechanical response of magnesium AZ31 processed using severe plastic deformation is characterized using a two-surface, pressure-insensitive plasticity model. The model captures the 3D plastic anisotropy and the tension–compression asymmetry as the behavior evolves during straining. The model may be viewed as a reduced-order quasi-crystal plasticity model, whereby the two activation surfaces represent glide- and twinning-dominated flow. The two-surface formulation enables independent, yet coupled, hardening laws in terms of effective plastic strains accumulated on either generic deformation system. Material identification was completed using tension and compression specimens oriented along the principal directions of the processed material, E, L, and F, as well as off-axes specimens that bisected the principal planes E–F, L–F, and L–E. Using the nominal stress–strain and lateral strain data from the experiments, this model can capture the anisotropic behavior of this material.
KeywordsOrthotropy Reduced-order model ECAE
JSH and AAB gratefully acknowledge support of this work by the National Science Foundation under grant number CMMI-1563580.
- 1.W. F. Hosford. The Mechanics of Crystals and Textured Polycrystals. Oxford University Press, Oxford, 1993.Google Scholar
- 6.B. Kondori, Y. Madi, J. Besson, and A. A. Benzerga. Evolution of the 3D plastic anisotropy of HCP metals: experiments and modeling. International Journal of Plasticity, 2018. In press.Google Scholar
- 8.R. Hill. A theory of yielding and plastic flow of anisotropic solids. Proceedings of the Royal Society of London A, 193:281–297, 1948.Google Scholar
- 12.M. Al-Maharbi, I. Karaman, I. J. Beyerlein, D. Foley, K. T. Hartwig, L. J. Kecskes, and S. N. Mathaudhu. Microstructure, crystallographic texture, and plastic anisotropy evolution in an Mg alloy during equal channel angular extrusion processing. Materials Science and Engineering: A, 528:7616–7627, 2011.CrossRefGoogle Scholar
- 16.D. W. Marquardt. An algorithm for least-squares estimation of nonlinear parameters. SIAM J. Appl. Math., 11:431–441, 1963.Google Scholar