Prediction of Material Flow Pattern in the Hot Extrusion of Aluminum Alloys by the Finite Element Method
Xavier Velay, Terry Sheppard and Xianjian Duan, Bournemouth University, United Kingdom
Track: DIE DESIGN AND TECHNOLOGY - Finite Element Method
ABSTRACT --- Understanding the material flow pattern in the hot extrusion of
aluminum alloys is useful to obtain better process control. The material flow pattern is
greatly affected by the friction between the tool and billet interface. In this
communication, an inverse analysis method is first adopted to match the calculated
extrusion force with the measured force by treating the friction law and the friction
coefficient as free parameters. Three widely accepted friction laws are investigated:
Tresca friction, Coulomb friction and viscoplastic friction. The use of Tresca friction is
shown to yield more accurate results and explanations than the other models. The
influence of the constitutive laws on the material flow pattern is emphasized. It is found
that use of the elasto-plastic model gives a much better prediction than use of the
visco-plastic model. It is also found that the quasi-static deformation is not fully
established until a short time after the peak load has occurred.
© Extrusion Technology for Aluminum Profiles Foundation (ET Foundation). All rights reserved. No part of The Proceedings may be reproduced in any form without the express written permission of the ET Foundation.