Metal Flow Analysis in Aluminium Extrusion - Microstructural Characterization and Modeling

摘要

In order to fully characterize the metal flow of an aluminium billet during the extrusion process, several modeling and simulation techniques can be employed. Material flow and strain distribution may be studied by a visioplasticity technique using model materials. Laboratory scale extrusion tests on engineering materials can be performed to determine the influence of processing parameters. The microstructural response of the material to processing variables may be obtained from a thermal - mechanical simulator, which accurately reproduces thermal cycles of extrusion. The crystallographic evolution of grains during thermal - mechanical treatment including the effect of die design and surface deformation conditions can be investigated via Electron Backscatter Diffraction (EBSD). Finally, the stress and temperature gradients can be calculated with Finite Element Modeling (FEM). The combination of these techniques, all applied to different aspects of the extrusion process, can provide a full account of how extrusion press conditions affect material flow and microstructure evolution. The work presented here has been applied to both solid and powder aluminium alloys.