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Modeling the Formation of Transverse Weld during Billet-on-Billet Extrusion Mahmoodkhani, Yahya; Wells, Mary; Parson, Nick; Jowett, Chris; Poole, W. J. (Warren J.)

Abstract

A comprehensive mathematical model of the hot extrusion process for aluminum alloys has been developed and validated. The plasticity module was developed using a commercial finite element package, DEFORM-2D, a transient Lagrangian model which couples the thermal and deformation phenomena. Validation of the model against industrial data indicated that it gave excellent predictions of the pressure during extrusion. The finite element predictions of the velocity fields were post-processed to calculate the thickness of the surface cladding as one billet is fed in after another through the die (i.e., the transverse weld). The mathematical model was then used to assess the effect a change in feeder dimensions would have on the shape, thickness and extent of the transverse weld during extrusion. Experimental measurements for different combinations of billet materials show that the model is able to accurately predict the transverse weld shape as well as the clad surface layer to thicknesses of 50 µm. The transverse weld is significantly affected by the feeder geometry shape, but the effects of ram speed, billet material and temperature on the transverse weld dimensions are negligible.

Item Metadata

Title
Modeling the Formation of Transverse Weld during Billet-on-Billet Extrusion
Creator
Mahmoodkhani, Yahya; Wells, Mary; Parson, Nick; Jowett, Chris; Poole, W. J. (Warren J.)
Publisher
Multidisciplinary Digital Publishing Institute
Date Issued
2014-04-30
Description
A comprehensive mathematical model of the hot extrusion process for aluminum alloys has been developed and validated. The plasticity module was developed using a commercial finite element package, DEFORM-2D, a transient Lagrangian model which couples the thermal and deformation phenomena. Validation of the model against industrial data indicated that it gave excellent predictions of the pressure during extrusion. The finite element predictions of the velocity fields were post-processed to calculate the thickness of the surface cladding as one billet is fed in after another through the die (i.e., the transverse weld). The mathematical model was then used to assess the effect a change in feeder dimensions would have on the shape, thickness and extent of the transverse weld during extrusion. Experimental measurements for different combinations of billet materials show that the model is able to accurately predict the transverse weld shape as well as the clad surface layer to thicknesses of 50 µm. The transverse weld is significantly affected by the feeder geometry shape, but the effects of ram speed, billet material and temperature on the transverse weld dimensions are negligible.
Subject
Extrusion; Transverse weld; Finite element method; Feeder; Aluminum alloys
Genre
Article
Type
Text
Language
eng
Date Available
2019-05-29
Provider
Vancouver : University of British Columbia Library
Rights
CC BY 3.0
DOI
10.14288/1.0379147
URI
http://hdl.handle.net/2429/70400
Affiliation
Applied Science, Faculty of; Non UBC; Materials Engineering, Department of
Citation
Materials 7 (5): 3470-3480 (2014)
Publisher DOI
10.3390/ma7053470
Peer Review Status
Reviewed
Scholarly Level
Faculty
Rights URI
https://creativecommons.org/licenses/by-nc-sa/3.0/
Aggregated Source Repository
DSpace

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CC BY 3.0