Narrow Results

This paper concentrates on the study of the superplastic response of coarse-grained Al-Mg alloys under uniaxial tension at different temperatures (ranging from 400°C to 525°C) and strain rates (10^-2 S^-1, 10^-3 S^-1 & 10^-4 S^-1). The microstructures have been analyzed using optical (OM) and transmission electron microscopy (TEM). It has been observed that continuous re-crystallization occurs during hot deformation of the alloy at the temperature of 425°C and strain rate of 10^-2S^-1. At the temperature of 425°C and strain rate of 3.78×10^-3S^-1, this Al-Mg alloy has the maximum elongation to failure of 181%, which is sufficient for manufacturing of extremely complex shapes using superplastic forming technology. The constant strain rate sensitivity index m and TEM observations show that in this case deformation mechanism involved is dislocation glide. Recrystallization during the hot tension greatly enhanced the plasticity of the coarse-grained material at a strain rate of about 10^-2S^-1 and the maximum elongation changes as a function of the strain rate.