Investigating the effect of rolling strain on fracture behavior of roll bonded Al6061 laminates under quasi-static and dynamic loading

Damage tolerance improvement has been reported by laminating aluminum alloys and composites by researchers. Three-layer laminates comprising Al6061 outer layers and Al1050 interlayer have been roll bonded in this research. While most of the works done have focused on fracture properties of roll bonded Al laminates in crack arrester geometry, this study explores their behavior in crack divider configuration. Rolling strain is varied to control the interfacial bonding in laminates. The fracture behavior of laminates and the constituent material was examined via three-point bending and impact tests. This study presents significant improvement in damage tolerance of laminates compared to their monolithic counterpart. This work also highlights the importance of debonding as an effective toughening mechanism in these laminates. At high strain rate condition, it is shown that improving the interfacial bonding by means of rolling strain can increase the damage tolerance of the laminate as far as delamination is not suppressed. Results of this study also show that increasing rolling strain can eliminate debonding at interfaces and reduce damage tolerance of laminate.