Numerical Simulation Research Of Aluminum Alloy Profile Pothole Extrusion Process

The use of aluminum alloy profile becomes more and more popular, because of their characteristics such as low weight, high strength as well as beautiful shape, etc. Extrusion is dominating manufacturing method of aluminum profiles. Traditionally, most of die design still use experience analogies, and trial-and-error over and over ensure the success rate of die design, which results in low efficiency, high cost and long developing period. Aluminum extrusion has the characteristics of diverse varieties and short production cycle. Therefore, how to speed up the analysis and modeling, reduce analysis time and increase computational efficiency means great significance for introducing the numerical simulation.Firstly, extrusion process and design principle of the porthole die is introduced. Subsequently, this paper mainly studies numerical simulation of the aluminum pothole extrusion. The principles and equations of arbitrary Lagrangian-Eulerian method(ALE) and the constitutive relation of A6063 at high temperature state are discussed. Using the HyperXtrude module based on the ALE method, steady state simulation on the extrusion process of the hollow aluminum profile is presented. It depicts the process of metal flow by Eulerian in the pocket and the process of free deformation by Lagrangian after bearing. The field distributions of velocity, temperature and strain rate of metal flow are obtained. They are basically consistent with the producing test, which conforms that this method may successfully predict the potential defects occurring in the actual extrusion process and provide the theoretical basis for process parameters selection and die design.Based on rigid plastic finite element method for steady analysis, a new aluminum profile pothole extrusion model is applied. Using MSC.Marc, numerical simulation in pothole extrusion process is presented. It sets adaptive minimum time step, which avoids mesh distortion and remeshing when finite element method deals with big deformation and accumulated error as a result of mesh flow at transient state. So it ensures the accuracy of the calculation. The results were analyzed in detail, and making use of the SDV value of flowing particles velocity at the exit, the equilibrium of velocity at the exit is quantitatively judged, which reveals how flowing velocity affects the shape and dimension of products. Compared with experiments, this method not only can greatly reduce the computational time cost, and guarantee of accuracy. So it can effectively simulate the material flow state in pothole extrusion process.