Stamp Forming of Polypropylene based Polymer-Metal Laminates: The Effect of Process Parameters on Spring Back

This paper investigates the effect of process parameters such as Blank Holder Force (BHF) and Feed Rate, on the spring back behavior of a polymer metal laminate (PML) system comprised of aluminum and polypropylene. Specimens were formed over a hemispherical punch in stamp forming process. A novel real time strain measuring system, ARAMIS, was employed to capture the strain evolution during forming. The results of this work indicate that both BHF and feed-rate exert influence in PML spring back behavior. Fundamental correlation between strain evolution during spring back and the shape of the finished part will be presented. A major finding from this work is that aluminum dominates the spring back behavior of PML in stamp forming.