Microstructure and mechanical properties of AlMg3 alloy in different hardening states during pulsed current assisted tensile deformation
Daniel Dobras, Z. Zimniak, M. Zwierzchowski, Mateusz Dziubek
Abstract
Pulsed current assisted deformation significantly expands the possibilities of forming light metal alloys such as aluminum alloys. However, the influence of individual current parameters on the microstructure and properties of the strain-hardened material depending on its hardening state is still unclear. In this study, the effect of pulse duration, pulse period and temperature on material behavior was analysed in the electrically-assisted tension of AlMg3 alloy in different hardening states. Two different hardening states were applied: annealed and strain hardened. The study showed that the effect of the pulse period is strongly dependent on the hardening state of the material, whereas the effect of the pulse duration is not. Moreover, it was shown that the average material temperature during pulsed current tension is not an important parameter, whereas the maximum temperature and the distribution are much more significant. Finally, electrically-assisted deformation of AlMg3 alloy leads not only to recovery and recrystallization of the microstructure, but also to precipitation of the Al 6 (Fe,Mn) phases, thereby changing the alloy hardening mechanism.