Abstract: The extrusion die plays a crucial role in the quality control of aluminum alloy profile production. Yet in practice, the design of extrusion die is mainly dependent on the experience and intuition of the designer, thus many times of modifications and experiments are needed to gain an acceptable product. The extrusion process of a complex hollow aluminum alloy profile is simulated by using ALE algorithm based HyperXtrude software, and the flow behavior of material and deformation mechanism in the die cavity are investigated. With the simulation results of the initial die design scheme, a non-uniform velocity distribution is observed. Thus two optimization schemes (establishment of double-step welding chamber at lower mold and introduction of baffle plate) are proposed to solve the problem. In addition, with the optimal die structure, the temperature and stress distribution in the cross-section of the profile become more even and the weld quality is also improved. The feasibility of die design and optimization method based on numerical simulation is validated, which can provide theoretical guidelines for the die design of the same kind profile.

Key words: Baffle plate, Double-step welding chamber, Hollow aluminum profile extrusion