Assessment of Metal Flow Balance in Multi-Output Porthole Hot Extrusion of AA6060 Thin-Walled Profile

Abstract

For the porthole hot extrusion of a thin-walled tube based on metal flow, the role of the die's structure should be focused on to achieve precision formation, especially for multi-output extrusion and/or complex cross-sectional profiles. In order to obtain a better metal flow balance, a multi-output porthole extrusion die was developed, including some novel features such as a circular pattern of the portholes with a dart-shaped inlet bridge, a buckle angle in the inlet side of the upper die, a two-step welding chamber, and a non-uniform bearing length distribution. Through the use of thermo-mechanical modeling combined with the Taguchi method, the underlying effects of key die features were investigated, such as the billet buckle angle, the porthole bevel angle, the depth of the welding chamber, and the type of bridge on the metal flow balance. The experimental validation showed that the developed numerical model for the multi-output porthole extrusion process had high prediction accuracy, and was acceptable for use in an industrial extrusion with a complex section.

A Design Approach of Porthole Die for Flow Balance in Extrusion of Complex Solid Aluminum Heatsink Profile with Large Variable Wall Thickness

“…The physical and thermal parameters of these materials are the same as those used by the HyperXtrude software library, as shown in Table 1. The continuous equation based on the Sellar-Tegart model, which is widely used in simulations of aluminum profile extrusion [9,10], is applied for the simulation, as described in Equation (1):…”

“…They introduced some modification steps to optimize the die structure, which included porthole correction, adding baffles, and fine-tuning bearing lengths. Xue et al [9] aimed at improving the flow balance during the extrusion of a thin-walled profile by multi-cavity die. By combining the FE analysis and Taguchi method, they determined preferable parameters for the die structure, such as the undercut angle of porthole entrance, the relief angle of the porthole, and the welding chamber height.…”

Material and Process Design for Lightweight Structures

“…The article by X. Xue et al [8] fills another knowledge gap related to the sophisticated production of hollow, thin-walled aluminum alloy profiles, used for example in the bodies of high speed trains. The challenging aspect of extruding such profiles lies in their complex cross sections, which renders material flow in the extrusion die cavity much complex and difficult to control.…”

Simulation Analysis of Porthole Die Extrusion Process and Die Structure Modifications for an Aluminum Profile with High Length–Width Ratio and Small Cavity

“…Also, the shortcoming of SS formulation can also be eliminated since the procedure is essentially incremental. In recent years, the application of ALE formulation in the simulation of porthole die extrusion process has been used even more extensively [ 10 , 11 , 12 , 13 , 14 ]. Therefore, in this study, the 3D-FE model for simulating the porthole die extrusion process of aluminum profile with small cavity was established using HyperXtrude software-based ALE formulation.…”

“…Through multiple adjustments, a uniform flow velocity at die exit is obtained. Xue et al [ 14 ] investigated the influence of key die structures such as the billet buckle angle, the porthole bevel angle, the depth of the welding chamber, and the type of bridge on the metal flow balance during multi-output porthole extrusion process through the use of thermo-mechanical modeling combined with the Taguchi method. Gagliardi et al [ 15 ] investigated the influences of geometric variables of porthole die on the extrusion load, the maximum pressure inside the welding chamber, and the material flow homogeneity by ANOVA technique.…”