Interface toughening of Al–Cu laminate composite

Different kinds of elasto-plastic mismatch and interface of laminate composite will lead to different mechanical properties. In this study a soft Al layer cladded on the surface of an Al alloy is adhered with the other component using explosive bonding. The strength of the Al layer is lower than that of adhesion of the interface, the crack will grow in this layer and the toughening effect can be evaluated. Experimental result shows that as two LY12 laminates are bonded, little interface effect is observed. The results of LY12/Cu laminate composite show that the delaminating crack results from low cycle fatigue. If the crack turns back and penetrates into the next laminate to the principal stress plane, the mechanism is crack re-initiation, as the stress level exceeds the fatigue limit of Cu.