FE analysis of extrusion defect and optimization of metal flow in porthole die for complex hollow aluminium profile
(1. State Key Laboratory of Advanced Design and Manufacture for Vehicle Body, Hunan University, Changsha 410082, China;
2. School of Mechanical Engineering, Hunan Industry Polytechnic, Changsha 410208, China;
3. School of Mechanical Engineering, University of South China, Hengyang 421001, China)
2. School of Mechanical Engineering, Hunan Industry Polytechnic, Changsha 410208, China;
3. School of Mechanical Engineering, University of South China, Hengyang 421001, China)
Abstract: To solve the defects of bottom concave appearing in the extrusion experiments of complex hollow aluminium profiles, a 3D finite element model for simulating steady-state porthole die extrusion process was established based on HyperXtrude software using Arbitrary Lagrangian–Eulerian (ALE) algorithm. The velocity distribution on the cross-section of the extrudate at the die exit and pressure distribution at different heights in the welding chamber were quantitatively analyzed. To obtain an uniformity of metal flow velocity at the die exit, the porthole die structure was optimized by adding baffle plates. After optimization, maximum displacement in the Y direction at the bottom of profile decreases from 1.1 to 0.15 mm, and the concave defects are remarkably improved. The research method provides an effective guidance for improving extrusion defects and optimizing the metal flow of complex hollow aluminium profiles during porthole die extrusion.
Key words: hollow aluminium profile; extrusion defect; metal flow velocity; baffle plate; ALE algorithm