Edge Crack Behavior and Strengthening Mechanism of Width-limited Rolled AZ31 Magnesium Sheet with Large Reduction

doi:10.3901/JME.2021.08.146

Abstract

Abstract: AZ31 magnesium alloy sheet has a broad application prospect in the field of lightweight including aviation, aerospace, automotive, electronics, weapons, etc. However, its plastic forming ability is so poor that it cannot withstand large rolling reduction in a single pass and easy to produce edge cracks. Traditional rolling and width-limited rolling are conducted on AZ31 sheet respectively. The results show that the actual maximum single rolling reduction can reach 50% and the length of edge crack is less than 2 mm under bidirectional compressive stress. However, serious edge cracks and fish-scale cracks in center region can be observed in AZ31 sheet fabricated by traditional rolling with 50% rolling reduction. Compared with as-received sheet, the strengthening mechanism of the width-limited rolled magnesium sheet is mainly dislocation strengthening. The yield strength and tensile strength of width-limited rolled sheet along the rolling direction increase by 54.7% and 54.1%, and along the transverse direction increase by 383.9% and 131.1%, respectively. The strength and elongation along the transverse direction of width-limited rolled sheet are higher than that along the rolling direction owing to its stronger refinement strengthening effect.

Key words: AZ31 magnesium alloy sheet, width-limited rolling, large rolling reduction, edge crack, strengthening

CLC Number:

TG33

NIE Huihui, ZHENG Liuwei, TIAN Jing, LIANG Wei. Edge Crack Behavior and Strengthening Mechanism of Width-limited Rolled AZ31 Magnesium Sheet with Large Reduction[J]. Journal of Mechanical Engineering, 2021, 57(8): 146-153.

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