Effect of Bending Variables on the Characteristics of EN-AW5018 Tubes for Subsequent Hydroforming

Abstract

Understanding the effects of forming history on the subsequent hydroformability of aluminum alloy tubes is critical for widespread acceptance of aluminum as a light-weight alternative in automotive components. The aim of this research is to investigate the influence of pre-bending on the characteristics of aluminum alloy tubes for the hydroforming process. Tube bending experiments were performed on 2 and 3.5 mm wall thicknesses with 76.2 mm outer diameter EN-AW5018 tube. In the tube bending experiments, key process parameters such as boost were varied and the effect on the resultant thinning, strains and springback of the as-bent tubes was assessed. Bending boost is shown to reduce thinning and strains in the as-bent tubes which has been found to be favourable for any subsequent hydroforming operation.

Understanding the effects of forming history on the subsequent hydroformability of aluminum alloy tubes is critical for widespread acceptance of aluminum as a light-weight alternative in automotive components. The aim of this research is to investigate the influence of pre-bending on the characteristics of aluminum alloy tubes for the hydroforming process. Tube bending experiments were performed on 2 and 3.5 mm wall thicknesses with 76.2 mm outer diameter EN-AW5018 tube. In the tube bending experiments, key process parameters such as boost were varied and the effect on the resultant thinning, strains and springback of the as-bent tubes was assessed. Bending boost is shown to reduce thinning and strains in the as-bent tubes which has been found to be favourable for any subsequent hydroforming operation.

Comprendre l'effet de l'histoire de formage sur l'hydroformabilité subséquente de tubes en alliage d'aluminium est critique quant à l'acceptation sur une grande échelle de l'aluminium comme remplacement de poids léger pour les pièces automobiles. Le but de cette recherche est d'étudier l'influence du pré-pliage sur les caractéristiques de tubes en alliage d'aluminium pour le procédé d'hydroformage. On a effectué des expériences de pliage sur des tubes EN-AW5018 de 2 et 3.5 mm d'épaisseur de paroi, avec un diamètre extérieur de 76.2 mm. Au cours des expériences de pliage, on a varié des paramètres clés du procédé, tels que la suralimentation, et l'on a évalué l'effet qui en résultait sur l'amincissement, les déformations et le retour élastique des tubes tels que pliés. On montre que la suralimentation de pliage réduit l'amincissement et les déformations des tubes tels que pliés, ce que l'on considère favorable pour toute opération subséquente d'hydroformage.