Tension-compression asymmetry and Bauschinger-like effect of AZ31 magnesium alloy bars processed by ambient extrusion

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2023-01, Vol.862, p.144353, Article 144353
• Main Authors: Peng, Jin-Hua, Zhang, Zhen, Chen, Huan-huan, Zang, Qian-Hao, Chen, Liang-Yu, Guo, Ting-Ting, Lu, Sheng
• Format: Article
• Language: English
• Subjects: Ambient extrusion; Asymmetry; Back stress; Bauschinger effect; Compacting; Compression tests; Compressive strength; Deformation effects; Deformation mechanisms; Extrusion billets; Magnesium base alloys; Mechanical twinning; Plastic deformation; Tension-compression asymmetry
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2022.144353

Ambient extrusion was used to introduce different pre-strains in billets of AZ31 magnesium alloy. The effect of the pre-strain on tension-compression asymmetry and Bauschinger-like effect were studied. During ambient extrusion, the experimental material experienced {101‾2} twinning, {101‾2} detwinning and {101‾1} twinning sequentially. During tension and compression tests, the dominating deformation mechanisms are different, thus the tensile and compressive yield strength are improved with different trends. The extruded billets showed the strongest tension-compression asymmetry and Bauschinger-like effect when the pre-strain was ∼11%. With further increase of pre-strain, the plastic deformation became more homogeneous and caused a higher strengthening effect on {101‾2} twinning. As a result, the tension-compression asymmetry and Bauschinger-like effect got gradually weakened.