On multi-scale strain localization in twinning Magnesium C. C. Aydıner∗ Department of Mechanical Engineering, Boğaziçi University, Istanbul 34342, Turkey ∗ can.aydiner@boun.edu.tr Keywords: magnesium, twinning, strain patterning, digital image correlation Magnesium alloys are the lightest structural metals, but their structural application is hampered by the complexity of their crystallite-scale deformation that operates with multiple slip and twin mechanisms. They are hence prime candidates to benefit from advanced polycrystalline models, and an extensive literature formed to address their anisotropic and load-path-dependent behavior. While these attempts typically seek validity in an aggregate-average sense, there is also a recent physics-based drive towards higher-fidelity modeling that can represent strain fields at some microstructural length scale. Over time, we have amassed spatially resolved in situ data that can counterpart such models, detailing the intergranular strain localization signature of wrought Magnesium AZ31 polycrystals. The method is an advanced in situ implementation of digital image correlation with optical microscopy that can employ high resolution objectives thanks to automated corrective measures. Further, full-field area scanning is utilized to reveal long range strain localization that is a huge issue for Magnesium alloys (e.g. Lüders-like twinning bands [1]). The presented studies will cover crystallographic texture dependence [2,5], cyclic loading and its effect on twin-based Lüders banding [3], inherited strain localization structures (via texture scars that form with renucleation in the previous forming process) [3,4], and interaction with stress raisers [5]. References [1]. Özdür, N. A., Üçel, I. B., Yang, J., Aydıner, C. C. (2021). Residual Intensity as a Morphological Identifier of Twinning Fields in Microscopic Image Correlation. Exp Mech, 61:499–514. [2] Kapan E, Shafaghi N, Uçar S, Aydıner CC (2017) Texture-dependent character of strain heterogeneity in Magnesium AZ31 under reversed loading. Materials Science and Engineering: A 684:706–711. [3] Shafaghi N, Kapan E, Aydıner CC (2020). Cyclic Strain Heterogeneity and Damage Formation in Rolled Magnesium Via In Situ Microscopic Image Correlation. Exp Mech 60:735–751. [4] Üçel İB, Kapan E, Türkoğlu O, Aydıner CC (2019) In situ investigation of strain heterogeneity and microstructural shear bands in rolled Magnesium AZ31. International Journal of Plasticity 118:233–251. [5] Erman, S.C., Stainier L., Aydıner, C. C. (2023). Guiding severely anisotropic twinning bands in Magnesium: An in situ investigation by full-field microscopic image correlation 122
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