The effect of forming passes on the springback and microstructure of magnesium alloy sheets in roll bending

• Published in: Materials today communications Vol. 42; p. 111292
• Main Authors: Wang, Rongjun, Xue, Sensen, Zhou, Weiguang, Wang, Xiaocong, Zhang, Pengchong, Wang, Jianhua, Yan, Yan, Meng, Zhijuan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2025
• Subjects: Forming passes; Magnesium alloy sheets; Microhardness; Microstructure; Roller bending forming; Springback angle; Magnesium alloy sheets; Roller bending forming; Forming passes; Springback angle; Microstructure; Microhardness
• ISSN: 2352-4928; 2352-4928
• DOI: 10.1016/j.mtcomm.2024.111292

Roll-bent components made from magnesium alloy sheets better meet application requirements for lightweight, damping, vibration reduction, and heat dissipation. This study employed finite element simulations and experimental methods to investigate the roll-bending behavior of AZ31B magnesium alloy sheets. Springback angles and microhardness at the bend angles were measured, and EBSD was used to analyze the microstructures on the compression and tensile sides during roll bending. Results show that during roll bending, significant twinning and grain refinement occur on the compression side at the bend angle, while twinning is less noticeable on the tensile side. For the same forming angle, multi-pass forming increases the springback angle due to a decrease in LAGB proportion on the compressed side and an increase in the proportion of {10−12}-{10−12} tensile twin variants on the tensile side. Multi-pass forming subjects the magnesium alloy sheet to repeated loading and unloading, resulting in a dispersion of the basal {0001} pole density in the ND direction and a reduction in TD texture strength on the compression side, while the basal plane texture on the tensile side weakens. The interaction between twin boundaries and dislocations, along with the increase in GND density, enhances dislocation pile-up, resulting in higher microhardness during multi-pass forming. The rise in LAGBs on the tensile side impedes and accumulates dislocations, leading to a higher GND density than on the compression side. Basal slip on the compression side transitions from a hard to soft orientations, with a slight decrease in the average SF of prismatic and pyramidal slip. [Display omitted] •The changes in hardness and springback during different forming passes were analyzed.•The fraction of LAGBs increases significantly on the multi-pass tensile side.•The GND density on the tensile side of the multi-pass roll bending forming is higher.•The {0001} pole density on the multi-pass compression side exhibits dispersion.