Benefits of Using Pre-Treated, Pre-Aged Aluminium 6xxx Sheet Material for Closure Applications

Weight reduction is the key argument for the application of aluminium in cars. However, the extra costs and its limited formability compared to steel slow down the increase in volume.

Application of dry lubricants improves the forming behavior as well as reduce the sensitivity to surface damage. A pre-treatment of the surface before assembly is necessary in order to guarantee a good durability of the joints. Cost optimization can be realized when downgauging possibilities of pre-aged material (Superlite^®) having an improved bake-hardening response are utilized. A further possibility for cost optimization at the car manufacturer is created when the supplier performs all three processing steps (pre-ageing, pre-treatment and dry-lubricant) in one continuous annealing and surface pre-treatment line.