Hot deformation and processing maps of Al-6Mg-0.4Mn-0.2Sc aluminum alloy

The hot deformation behavior of Al-6Mg-0.4Mn-0.2Sc aluminum alloy was investigated by hot compressive tests on Gleeble-1500 thermal simulation test machine at 300-500℃and strain rates of 0.001-10 s-1.The stress exponent and the deformation activation energy at elevated temperatures were calculated.The constitutive equation of the plastic deformation of Al-6Mg-0.4Mn-0.2Sc alloy at elevated temperatures was obtained by introducing Zener-Hollomon parameter.The processing maps were calculated and analyzed according to the dynamic materials mode.The results show that the flow behaviour is described by the hyperbolic sine constitutive equation,and an activation energy of 158.92 kJ/mol is greater than the activation energy for self-diffusion in Al.The process of hot deformation in the temperature range and different strain rate can be attained by the maps.The hot deformation temperature is 430-480℃,strain rate is around 5-10 s-1,warm deformation temperature is 320-400℃and strain rate is 0.01-0.001 s -1.The instability zones of flow behaviour can also be recognized by the maps.