Twin-induced hardening in extruded Mg alloy AM30
Twin-induced hardening in extruded Mg alloy AM30
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DOI：
10.1016/j.msea.2016.12.123
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发表时间：
2017-02
期刊：
影响因子：
6.4
通讯作者：
H. Qiao;Xiaoqian Guo;A. Oppedal;H. Kadiri;Peidong Wu;S. Agnew
中科院分区：
文献类型：
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作者：
H. Qiao;Xiaoqian Guo;A. Oppedal;H. Kadiri;Peidong Wu;S. Agnew
最近在实验和数值上研究了挤压镁合金AM30的机械各向异性（Oppedal等人，2013 [1]）。作者强调，除了孪生贡献占主导地位或可忽略不计的有限情况外，还需要将中间水平孪生的情况作为关键验证。然而，对结果的进一步审查表明，该研究中采用的实验数据仍然不足以约束晶体塑性模型中的所有必要参数。特别是，描述棱柱滑移机制的参数是约束不足的。在本研究中，获得了额外的实验数据，以提供必要的约束。基于这些实验结果，可以得出更清晰的结论，晶体塑性模型的要求，它必须准确地考虑强拉压不对称性以及强度和应变硬化行为的各向异性。除了先前采用的粘塑性自洽（VPSC）模型，与占主导地位的孪晶重取向（PTR）计划，弹性粘塑性自洽（EVPSC）模型，与最近发展的孪生和去孪生（TDT）描述，被应用于模拟沿沿着任意方向的单轴响应。它表明，占初始纹理和校准的EVPSC-TDT模型使用单轴拉伸和压缩沿着挤压方向允许预测强度各向异性和应变硬化行为沿着任意应变方向。
The mechanical anisotropy of extruded Mg alloy AM30 was recently investigated, both experimentally and numerically (Oppedal et al., 2013 [1]). The authors highlighted the need to include cases of intermediate levels of twinning as a critical validation, in addition to the limiting cases where the contribution of twinning is dominant or negligible. However, further scrutiny of the results revealed that the experimental data employed in that study were still inadequate to constrain all necessary parameters in the crystal plasticity models. In particular, the parameters describing the prismatic slip mechanism were under-constrained. In the present study, additional experimental data were obtained to provide the necessary constraint. Based upon these experimental results, clearer conclusions can be drawn about the requirements of a crystal plasticity model, which must accurately account for strong tension-compression asymmetry as well as anisotropy in both strength and strain hardening behavior. In addition to the previously employed Viscoplastic Self-Consistent (VPSC) model, with the Predominant Twin Reorientation (PTR) scheme, the Elastic Visco-Plastic Self-Consistent (EVPSC) model, with the recently developed Twinning and De-Twinning (TDT) description, is applied to simulate the uniaxial response along arbitrary directions. It is demonstrated that accounting for the initial texture and calibrating the EVPSC-TDT model using uniaxial tension and compression along the extrusion direction permits prediction of the strength anisotropy and strain hardening behavior along arbitrary straining directions.