Surface strain evolution of ultrafine-grained aluminum alloy laminates under tension - Microscale plastic instabilities and the Portevin-Le Chatelier effect

The surface strain evolution in accumulative roll bonded aluminum alloys was studied in situ using digital image correlation. Laminated multicomponent materials, consisting of two ultrafine-grained aluminum alloys with different layer architectures (laminate and sandwich), were analyzed and compared to the pure alloys after the same number of accumulative roll bonding cycles. The results obtained show differences in the surface strain evolution of the accumulative roll bonded and differently stacked materials, which is attributed to microscale plastic instabilities.