Al-4cu-of Mg Alloy Semi-solid Forming

It is important to study deformation behavior, deformation mechanism and microstructure evolution of semi-solid alloys because the semi-solid alloy has special characterization. To establish the constitutive relationship consistent with practice and couple with plastic deformation and heat transfer will be beneficial to realize the distribution of stress, strain and temperature raise during the deformation processes. To predict whether defects occur or not and optimize the process parameters could provide scientific foundation of metal forming.In this paper, deformation behavior of the semi-solid Al-4Cu-Mg alloy has been investigated by isothermal compression. Effect of the process parameters, including deformation temperature, strain and strain rate, on deformation behavior has been deeply discussed. Based on the deformation behavior of semi-solid Al-4Cu-Mg alloy, a constitutive relationship of semi-solid alloy has been established. It has been proved to be a simple model, which can represent the deformation behavior of semi-solid alloys.Writing the constitutive relationship to FE code, a coupled simulation of plastic deformation with heat transfer has been carried out in the backward extrusion of semi-solid Al-4Cu-Mg alloy. Effect of the process parameters, including deformation temperature, punch velocity, height reduction, extrusion ratio and shear factor of friction on the equivalent stress, the equivalent strain and the temperature raise during the semi-solid backward extrusion has been studied.Finally, backward extrusion of semi-solid Al-4Cu-Mg alloy has been carried out. The experimental result is in agreement with the calculated result in the initial stage and final stage. Meanwhile, microstructure evolution might affect the deformation behavior in the semi-solid state and should be studied deeply.