3D finite element analysis of metal flow in hot aluminium extrusion of T-shaped profile with various offset pockets

• Autorzy: Carmai S. J. J. , Pitakthapanaphong S. , Sechjarern S.
• Języki publikacji: EN

Abstrakty

EN

Purpose: The present paper has therefore investigated influence of offset pocket design on metal flow behaviour in hot aluminium extrusion of a T-shaped profile. Design/methodology/approach: A series of finite element simulations have been carried out by offsetting the centre of pocket cross-section and examining exit velocity distributions of the profile cross-section for each case. Findings: That the offset pocket has influence on the metal flow during extrusion process. Small distance between the edge of the pocket and the edge of the die leads to slow flow velocity but if the distance is large the metal can flow through easily, hence higher velocity. With the information from the analyses, the new pocket was proposed. The velocity difference across the cross-section of the extrude was smaller compared to the original pocket. The extrudate is straight and not bent. Offsetting pocket can therefore be used to control metal flow to the die. Practical implications: The appropriate design of pocket will help in regulating the metal flow and lead to a single bearing length or even zero length bearings. This is more favorable than a flat die with varying bearing lengths as a pocket die could be more easy to machine or correct especially extrusion of a thin walled profile. The pocket is usually required for extrusion of complex geometries. The fundamental understandings of pocket design are currently inadequate. It depends heavily on the experience of the die designer. Limited work has been done towards systematically examining influences of the pocket geometries and offsets on metal flow. Originality/value: The present paper has therefore investigated influence of offset pocket design on metal flow behaviour in hot aluminium extrusion of a T-shaped profile of which its cross-sectional width varies. Its shape factor is 6.76. The thermal effect has also been incorporate. An appropriate pocket die design for a T-shaped profile has later been proposed.

Słowa kluczowe

EN

extrusion; finite element model; aluminium; die design; pocket design; metal flow

• Wydawca: International OCSCO World Press
• Czasopismo: Journal of Achievements in Materials and Manufacturing Engineering
• Rocznik: 2008
• Tom: Vol. 31, nr 2
• Strony: 463--468
• Opis fizyczny: Bibliogr. 8 poz., wykr.

Twórcy

autor

Carmai S. J. J.

autor

Pitakthapanaphong S.

autor

Sechjarern S.

• Department of Production Engineering, Faculty of Engineering, King Mongkut's University of Technology North Bangkok, Bangkok, Thailand,

Bibliografia

• [1] G. A. Lee, Y. T. Im, Analysis and die design of flat-die hot extrusion process 2. Numerical design of bearing lengths, International Journal of Mechanical Sciences 44 (2002) 935-946.
• [2] Q. Li, C. J. Smith, C. Harris, M. R. Jolly, Finite element investigations upon the influence of pocket die designs on metal flow in aluminium extrusion. Part I. Effect of pocket angle and volume on metal flow, Journal of Materials Processing Technology135 (2003) 189-196.
• [3] Q. Li, C. J. Smith, C. Harris, M. R. Jolly, Finite element investigations upon the influence of pocket die designs on metal flow in aluminium extrusion. Part II. Effect of pocket geometry configurations on metal flow, Journal of Materials Processing Technology 135 (2003) 197-203.
• [4] Z. Peng, T. Sheppard, Effect of die pockets on multi-hole die extrusion, Materials Science and Engineering A 407 (2005) 89-97.
• [5] I. Flitta, T. Sheppard, Nature of friction in extrusion process and its effect on material flow, Materials Science and Technology 19 (2003) 837-846.
• [6] T. Sheppard, Extrusion of aluminium alloys, Dordrecht, Kluwer Academic Press, 1999.
• [7] J. Lof, Elasto-viscoplastic FEM simulations of the aluminium flow in the bearing area for extrusion of thinwalled sections, Journal of Materials Processing Technology 114 (2001) 174-183.
• [8] S. Butdee, S. Poomsawat, P. Martin, Analysis of the aluminium extrusion by finite element method, Proceedings of the 7th International Conference ”Manufacturing and Management”, November 27-29, 2002, 494-499.