Aluminium Alloy Selection for Closures with Respect to Functional Demands

The choice of alloys for closures is dependent on the functional requirements such as dent resistance, torsional rigidity, feasibility of the panel and corrosion resistance. Based on its good hemming performance, low FFC susceptibility and high formability AA6016 is the preferred alloy choice for outer panels in Europe. With the newly developed pre-bake qualities 6016 T4P having an improved Bake-Hardening-Response for conventional paint lines the requirement for dent resistance is no longer a limiting factor for downgauging. When torsional rigidity is the most critical demand for closures the 6016/5182 as outer/inner combination provides the best weight saving solution.