Impact of Aluminium Ageing in an Industrial Stamping Process

¹ IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
² MCG, Manuel da Conceição Graça, Rua Manuel da Conceição Graça, 2580-462 Carregado, Portugal

^* Corresponding author: joao.magrinho@tecnico.ulisboa.pt

Abstract

The automotive industry's efforts to reduce vehicle weight are driving the increasing adoption of aluminium alloys in vehicle chassis components. However, using aluminium alloys introduces challenges in forming processes, influenced by diverse factors such as material storage conditions and natural ageing, which can affect the formability. The present study investigates the effect of natural ageing on the formability of the AW 5754-H111 alloy by examining two storage conditions: as received (no ageing) and aged for two months. Formability tests were performed to characterise the mechanical behaviour and determine the material's formability limits. During these tests, the Portevin-Le Châtelier (PLC) effect, a plastic deformation instability, was observed. Its temperature dependence was further examined through controlled-temperature tests. Additionally, the study incorporated experimental and numerical analyses of an industrial stamping process for a component made from this alloy. Key findings include the characterisation of formability limits under different ageing conditions in the principal strain space, an analysis of the PLC effect across diverse temperature ranges and fracture modes, and validation of numerical models against experimental results for the diverse stamping stages. This work provides valuable insights into the mechanical performance of aged aluminium alloys in industrial applications.