Modeling the effect of Mg addition on microstructure and strength of aluminum during severe plastic deformation

Although Al-Mg alloys have various desirable properties, to broaden the applications, it is needed to increase the strength of these alloys. Severe plastic deformation (SPD) is a candidate method for this purpose. In this paper, a model is presented for the strength and microstructure evolution during severe plastic deformation. The model is applied to 5 Al-Mg alloys with different solute contents of 1, 2, 3, 4, and 5 wt% Mg. The model is also employed for pure Al for the sake of comparison. The model evaluates the effectiveness of Mg addition, quantitatively. It is shown that the combining of solute addition and severe plastic deformation can provide a considerable increase in the strength of Al-Mg alloys. Moreover, it is shown that adding Mg solute to pure Al changes the value of the dislocation density more than the values of the cell size and strength. The model also considers two effects for the presence of Mg solute as implicit and explicit effects. Then, the quantitative evaluation is performed. It indicates that the ratio of the effects is dependent on solute content, and the implicit one plays a more significant role.