Mariana POP, Dan FRUNZA


The aim of the paper is to present the influence of friction conditions on the flow of material in the processes of plastic formation of metals. Insufficient knowledge of the interface between the material and the forming tools is a factor for which the phenomenon of friction is not fully known. Due to friction the deformation of the material occurs unevenly. The non-uniformity of the deformation is greater the more the friction is accentuated. In order to determine the influence of the friction state on the material flow, experiments were performed for: the determination by the ring method of the friction coefficients in the case of three types of friction states; determination of the influence of the deformation energy on the formability of the material depending on the coefficient of friction at the surface of the sample-tools.

Full Text:



Altan T., Ngaile G., Shen G., Cold and Hot Forging, Fundamentals and Applications, ASM International, 2004

Joun MS, Moon HG, Choi IS, Lee MC, Jun BY. Effects of friction laws on metal forming processes. Tribology International 2009;42:311–9

Abtahi S. Interface mechanisms on the bearing surface in extrusion. Sixth international aluminium extrusion. Michigan USA; 1996. p. 125–131.

Bakhshi-Jooybari M. A theoretical and experimental study of friction in metal forming by the use of the forward extrusion process. Journal of Materials Processing Technology 2002;125–126:369–74.

Flitta I, Sheppard T. Nature of friction in extrusion process and its effect on material flow. Journal of Materials Science and Technology 2003;19:837–46.

F.P. Bowden, D. Tabor, The Friction and Lubrication of Solids, Oxford University Press, Oxford, 1950

W.R.D.Wilson, S. Sheu,Real area of contact and boundary friction in metalforming, International Journal of Mechanical Sciences 30 (Nr7) (1988) S475–S489,

N. Bay, T. Wanheim, Real area of contact and friction stress at high pressure sliding contact, Wear 38 (1976) S201–S209

G.G. Adams, M. Nosonovsky, Contact modeling—forces, Tribology International 33

(2000) S431–S442

B.-A. Behrens, M. Alasti, A. Bouguecha, T. Hadifi, J. Mielke, F. Schäfer, Numerical and experimental investigations on the extension of friction and heat transfer models for an improved simulation of hot forging processes, International Journal of Material Forming 2 (2009) 121–124

Kunogi M. A new method of cold extrusion. Journal of the Scientific Research Institute 1956;50:215–45

Male AT, Cockcroft MG. A method for the determination of the coefficient of friction of metals under conditions of bulk plastic deformation. Journal of the Institute of Metals 1964-65;93:38–45

Handbook of Workability and Process Design Edited by George E. Dieter Howard A. Kuhn S. Lee Semiatin, ASM International.2003

Wanheim, T., Bay, N., 1978. A model for friction in metal forming processes. Ann. CIRP 27,189-194

Wanheim, T., Bay, N., Peterson, A.S., 1974. A theoretically determined model for friction in metal working processes. Wear 28, 251-252

ASM Handbook, vol.18, Friction, Lubrication and Wear Tehnology, ASM International

Rus A., Frunză D., Hot deformation behavior for a thermomechanical processed 2014 aluminum alloy by tensile test, Acta Technica Napocensis, Series: Applied mathematics, mechanics and engineering, Vol 58, Issue III, 2015;

Rus A., Effect of thermo-mechanical treatments on the hot deformation, Acta Technica Napocensis, Series: Applied mathematics, mechanics and engineering vol 60, Issue III ,2017,

Pop M. , Neag A. , Frunza D., Popa F., Thermomechanical analysis of plastic deformation behaviour in dieless drawing

of metallic materials, Acta Technica Napocensis, Series: Applied mathematics, mechanics and engineering, Vol 63, No 2 2020.


  • There are currently no refbacks.