Effect of cryorolling on the mechanical properties of AA5083 alloy and the Portevin-Le Chatelier phenomenon

The effect of cryorolling on the mechanical properties of an AA5083 alloy was investigated. The effect of rolling strain and temperature on the Portevin-Le Chatelier effect experienced by aluminium alloys with magnesium as a major constituent was also studied. Microstructure evolution during room temperature (RT) and cryorolling (LNR) and their effect on the mechanical properties of the AA5083 alloy were studied in detail. The results showed that the hardness values increased as the rolling reduction was increased. Compared to RT rolling, LNR did not have a significant influence. Deformation-induced precipitation particles of Al6Mn during RTR resulted in enhanced mechanical properties compared to LNR conditions. A negligible amount of precipitation was observed due to suppressed adiabatic heating for samples under LNR conditions. The presence of manganese (more than its solid solubility limit) in the test material could have influenced the behaviour of the AA5083 alloy material upon rolling. The Portevin-Le Chatelier effect was clearly observed, and it was noted that with smaller grain size and an increasing dislocation density, the critical strain for the onset of the PLC effect was lowered. (C) 2014 Elsevier Ltd. All rights reserved.