Process Design for Electromagnetic Forming of Magnesium Alloy AZ31 Using FE Simulation

Abstract

Magnesium wrought alloys are outstanding lightweight materials due to their low density and high specific strength. The low formability of magnesium wrought alloy AZ31 at room temperature is increased by electromagnetic forming in comparison to quasi-static forming. For a detailed study of electro-magnetic process a coupled FE simulation must be performed. In this paper the process design for electromagnetic forming of magnesium wrought alloy AZ1 using FE simulation is presented. The complexity of an electromagnetic forming process requires the illustration of magnetic, thermal and structural dynamic domains. Moreover, it is also necessary to illustrate the electromagnetic resonant circuit RLC. Short processing time and the strong dependence of the physical domains to each other requires a coupled FE simulation. The illustration of resonant circuit and the resulting formation of magnetic field is carried out in two-dimensional rotationally symmetric model in ANSYS MAPDL using a suitable material model. As a result time-dependent and location-dependent eddy currents and Lorentz forces are estimated. Subsequently, the transmission of the estimated Lorentz forces and joule heat generation rates to ANSYS LS-DYNA is done. Due to the rotational symmetry of 2D ANSYS MAPDL model a transformation of the loads on 3D structures can be realized. The formation of an optimum deformation of a work piece in dependence of a defined die has been carried out. Here, the influence of different coil designs, die materials and geometries and RLC parameters was investigated.