Effect of heat treatment on microstructure and mechanical property of roll-bonded 1060/7N01/1060 laminates

Abstract

1060/7N01/1060 laminated composites with reliable bonding interfaces were successfully fabricated via single-pass hot rolling at 475 °C. The effects of layer thickness ratios on microstructure and mechanical property of synthesized laminates were studied using scanning electron microscope, transmission electron microscope and electron backscattered diffraction technique accompanied with hardness and tensile testing. Moreover, microstructure and mechanical property of DCR (direct cold rolling) and ACR (solution annealing and peak ageing plus cold rolling) samples were also explored. The results show that layer thickness ratios have little effect on microstructure of each layer in hot-rolled sheets, and their mechanical properties are consistent with theoretical predictions based on the rule of mixture. In comparison, extra heat treatment has no obvious effect on grain size of pure aluminium layers. However, smaller strip-like grains along with dispersed, finer precipitates are formed in 7N01 layer of ACR samples, leading to stronger grain refinement strengthening, precipitation strengthening and dislocation strengthening.