Finite element simulation and experimentational studies on inhomogeneous metal flow of alluminium extrusions for three dimensional complex geometries

Aluminium extrusions with complex geometries are simulated in three-dimensions using the finite element method (FEM) and experiments were also carried out to investigate the behaviour of metal flow, exit velocities, and heat transfer for a simple channel and a more complex geometry profile. This study clearly shows that with both designed extrusions, at the initial stage of extrusion the metal flow is inhomogeneous, and even a slight inhomogeneity of metal flow can significantly affect the final geometry of extrudates. Both the FEM and experiment demonstrated that the extrudates are bent and twisted for a complex extrusion profile. The complex distortion patterns were analysed in detail and related to their cause: inhomogeneous flow behaviour. The inhomogeneous flow pattern for a complex geometry profile was also revealed through FEM. The factors which could influence the quantitative results of the FEM were also discussed.