An exponential material model for prediction of the flow curves of several AZ series magnesium alloys in tension and compression

This paper is concerned with flow behaviors of several magnesium alloys, such as AZ31, AZ80 and AZ81, in tension and compression. The experiments were performed at elevated temperatures and for various strain rates. In order to eliminate the effect of inhomogeneous deformation in tensile and compression tests, the Bridgeman’s and numerical correction factors were respectively employed. A two-section exponential mathematical model was also utilized for prediction of flow stresses of different magnesium alloys in tension and compression. Moreover, based on the compressive flow model proposed, the peak stress and the relevant true strain could be estimated. The true stress and strain of the necking point can also be predicted using the corresponding relations. It was found that the flow behaviors estimated by the exponential flow model were encouragingly in very good agreement with experimental findings.

► The exponential model can represent flow behaviors of AZ series Mg alloys very well.
► Strain rate sensitivities of AZ series Mg alloys in compression are nearly the same.
► Effect of zinc element on tensile activation energy is higher than on compressive one.
► Activation energies of AZ80 and AZ81 in tension were greater than in compression.
► Tensile and compressive rate sensitivities of AZ80 are not close to each other.