Experimental study and modelling of v bending process of aluminium copper clad sheets

Abstract

Recently, laminated sheets or clad metal sheets with two or more layers of dissimilar metals have been developed as multifunctional materials. They combine the properties possessed by the base materials and provide enhanced properties including light weight, better mechanical and thermal properties, and high corrosion and wear resistance. Owing to this they are increasingly used in various industries such as automobile, electrical, ship, food and construction. Aluminium-Copper clad sheet is one such material which is widely used as electrical elements and heat conductive elements because of higher magnetic shielding, heat conductivity, corrosion resistance, lighter weight and lower price than pure copper or copper alloys. Press brake bending is one of the widely used sheet metal forming process to manufacture different types of bent parts. V-bending is the most commonly used bending process in which the sheet metal is pressed into a V shaped die using a V-shaped punch to form a required angular bend. When the punch is removed after the operation, due to elastic recovery, the bent angle varies. This shape discrepancy is known as springback which causes problems in the assembly of the component. The springback is to be predicted to provide compensation in tooling for eliminating springback. The force required to deform the sheet plastically is bend force and the prediction of bend force is essential for deciding the tooling and press. The change in thickness of the sheet should be within the limit and when it is more, it becomes a weaker point of failure. These three bending performances related to bending are influenced by various parameters. The study of bending behaviour of clad sheets becomes critical than the monolithic sheets as it constitutes different metals which have different properties and behaviour. This work encompasses the experimental study, development of prediction models and optimisation of parameters during V bending of Al/Cu bimetallic sheets.A detailed experimental study has been conducted to