Prediction of hardness of Al alloys processed by accumulative roll bonding

A recently developed grain refinement and strengthening model for oxide-free Al alloys processed by Severe Plastic Deformation (SPD) is tested and subsequently further developed to address Accumulative Roll Bonding (ARB) processed Al alloys. The model accurately predicts the grain refinement and the hardness of an ARB processed alloy. Compared to other SPD processes, oxide inclusions at the bonded surfaces cause additional grain refinement and hardening. The model also reveals that the hardness measured on the large surface of ARB processed Al alloys overestimates the volume averaged hardness of the material due to artifacts caused by the sample preparation and the indentation depth.