Abstract
The commercial magnesium alloy AZ31 has been subjected to a range of solution treatment regimes. These have then been extruded and their microstructure, texture, and precipitate populations characterized along with their mechanical properties. During the solution treatment, Mn-enriched particles develop and these remain largely unchanged throughout subsequent processing steps. A direct link between grain size and texture has been found, with coarser-grained specimens showing sharper textures. VPSC modeling has been used to quantify the effect of texture on the tensile yield strength, and it has been found that sharper textures have larger tensile yield strengths. Since coarser grain sizes have reduced Hall–Petch hardening, but have an additional texture-strengthening component, a region on the Hall–Petch plot for tension has been identified in which there is an insensitivity of strength to grain size. This has been quantitatively modeled and a texture-modified Hall–Petch plot for tension has been developed. The Mn-rich particles have also been shown to provide precipitate strengthening to the alloy of up to 40 MPa. The compressive behavior was clearer, with the compressive yield strength being directly correlated to grain size and unaffected by texture or precipitation hardening.
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Acknowledgments
The work described in this paper was funded by the Australian Research Council’s Centre of Excellence for Design in Light Metals. The authors would like to thank Mohan Setty, Andrew Sullivan, Kevin Magniez, and Rosey Van Driel for their assistance with the experimental sections of this work. Discussions with Matthew Barnett and Adam Taylor are also gratefully acknowledged.
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Manuscript submitted December 17, 2012.
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Stanford, N., Atwell, D. The Effect of Mn-rich Precipitates on the Strength of AZ31 Extrudates. Metall Mater Trans A 44, 4830–4843 (2013). https://doi.org/10.1007/s11661-013-1817-5
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DOI: https://doi.org/10.1007/s11661-013-1817-5