Arrhenius type constitutive equation for extruded plate of AlMg۶ alloy using plane strain compression test

The traditional and most common aluminum magnesium alloys are series ۵۰۰۰ and ۶۰۰۰ which have up to maximum value of ۴.۵% Mg. The presence of magnesium element in these alloys increases the strength and hardness, but, on the other hand, intensifies the intergranular corrosion. Recently, high-strength Al-Mg alloys have been developed by adding more Mg to amounts of greater than ۶% and therefore higher strength and softness. The weakness of these alloys due to higher sensitivity to intergranular corrosion can be decreased by thermomechanical treatment or hot forming. The present research is conducted with the aim of investigating the behavior of AlMg۶ alloy and providing a constitutive model based on the plane strain compression test. For this purpose, a special fixture is designed and built with proper dimensional and geometrical tolerance. The experiments are carried out at temperatures of ۳۰-۱۴۰°C and strain rates of ۰.۰۰۲-۰.۰۰۶ s-۱. From the obtained flow curves, the maximum stresses are determined and used in Arrhenius expression to extract the constants of the constitutive equation. The results of this model are in a good agreement with the experimental ones and therefore it can be used in the modeling and simulation of deformation processes that require the constitutive equation of this alloy.

Keywords:

Al-Mg alloy , Constitutive equation , Flow curve , Plane strain compression test