Abstract: The extrusion die plays a crucial role in the process of aluminum alloy profile production and its design determines the quality of products. However, the design of extrusion die in practice mainly depends on the traditional design experience, thus many times of modifications and experiments are needed to gain an acceptable product.The geometrical solid model of the porthole die for an aluminum multi-cavity wallboard profile is established by using UG. The extrusion process of the multi-cavity wallboard profile is simulated by using arbitrary Lagrange-Euler (ALE) algorithm based HyperXtrude software. The distributions of the velocity field, the temperature field and the stress field in the extrusion process are investigated and the metal flow process is analyzed in details. With the simulation results of the initial die design, a non-uniform velocity distribution is observed. To solve the problem of the non-uniform velocity distribution, three steps of the die optimization for the multi-cavity wallboard profile are proposed, including establishment of drainage channel, introduction of baffle plate and optimization of die bearing. The optimization results show that the die optimization method based on numerical simulation is valid and it can provide guidelines for the die design of the same kind profiles.

Key words: Multi-cavity wallboard, Numerical simulation, Three steps of die optimization