Modeling the Formation of Transverse Weld during Billet-on-Billet Extrusion

Materials

Yahya Mahmoodkhani¹  Mary Wells¹  Nick Parson²  Chris Jowett² 

[1] Mechanical and Mechatronics Engineering Department, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L3G1, Canada; E-Mail:;Rio Tinto Alcan, Arvida Research and Development Centre, Jonquiere, QC G7S4L2, Canada; E-Mails:

关键词: extrusion;    transverse weld;    finite element method;    feeder;    aluminum alloys;   

DOI  :  10.3390/ma7053470

来源: mdpi

【 摘 要 】

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.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland