Modelling and simulation of the grain deformation during extrusion of aluminium casting alloy (LM6) by finite element method

In any metal forming process, there's a high values of stresses and friction forces will generates due to sever interference between the contact surfaces. Extrusion process of aluminium casting alloy (LM6) is an obvious example for this case. Investigate the behavior of internal dislocation during the process is the main key to control the parameters which effects on the process efficiency. During this analysis; it's assumed that, the effects of some of extrusion conditions on the grain size distribution after extrusion like (ram speed and extrusion temperature) will be neglected. Microstructure changes of aluminium casting alloy (LM6) are used to study by a combination of numerical analysis using finite element technique and experimental process. The commercial code (ABAQUS/ CAE) software was adopted for analysis and simulation the thermo-mechanical behavior of the grain size and microstructure during this process, and investigates conditions on grain thickness distribution after the of extrusion. Scanning Electron Microscopy (SEM) used to show the microstructure before and after extrusion. Finite Element results reveals that; the homogeneous of the extruded shape is depend on the condition of the as - cast billet as well as the initial billet temperature. It was found through simulation process that the grain size is small in the center of the deformed extrudate and this size will increase gradually near the surface. Also, it's observed from the microstructures test that there is a transition in all Non-Recrystallized extrudates particles at the center is different from those at the surface. As a conclusion, it's found that there is a high effect for temperature and extrusion ratio on grain size and their distribution.