TITLE:
Effects of Pre-Strain on Bake Hardenability and Precipitation Behavior of Al-Mg-Si Automotive Body Sheets
AUTHORS:
Guanjun Gao, Lizhen Yan, Xiwu Li
KEYWORDS:
Al-Mg-Si Alloy, Pre-Strain, Bake Hardenability, Precipitation Behavior, Clusters
JOURNAL NAME:
Journal of Materials Science and Chemical Engineering,
Vol.12 No.7,
July
31,
2024
ABSTRACT: The study investigates the effects of pre-strain on the bake hardenability and precipitation behavior of Al-Mg-Si automotive body sheets. The scanning electron microscopy, transmission electron microscopy, tensile test, Vickers hardness test, and differential scanning calorimetry were conducted for the purpose. It was found that the pre-strain treatment partially inhibits the natural aging hardening effect but cannot completely eliminate it. The pre-straining significantly enhances the bake hardening effect, with the 5% pre-strain sample showing the highest increase in yield strength and hardness. The formation of fine β precipitates and dislocation structures contribute to the observed strengthening. Additionally, the study highlights the importance of optimizing pre-strain levels to achieve the best balance between strength and ductility in bake-hardened aluminum alloys.