Prediction of fracture onset in flashless warm forging Mg alloy AZ61

Prediction of fracture onset in flashless warm forging Mg alloy AZ61

Piotr Skubisz, Łukasz Lisiecki

AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Krakow, Poland.



The paper presents an innovative precision forging process, highlighting the use of advanced simulation of net forging process in multiple-tool die set with consideration of counter-pressure and interaction of components so as to control tool speed and displacement of metal. In addition to the use of finite element method in optimization of process conditions, damage criteria have been formulated to investigate the effect on plasticity and tendency of formation of defects and define process conditions which contribute to cracking occurrence in warm forging of magnesium alloy AZ61. Both forged samples and numerical simulation prediction indicate minimization of cracking hazard in lower work-temperature range at relatively high strain rate by employing counter-pressure imposing hydrostatic component into state of stress.

Cite as:

Skubisz, P., & Lisiecki, Ł. (2019). Prediction of fracture onset in flashless warm forging Mg alloy AZ61. Computer Methods in Materials Science, 19(3), 100-106.

Article (PDF):


Magnesium alloy AZ61, Warm forging, Fracture criteria, Workability


Avedesian, M.M., (ed.), 1999, ASM Specialty Handbook. Magnesium and Magnesium Alloys, The Materials Information Society, 314.

Burgdorf, M., 1967, Über die Ermittlung des Reib-wertes für Verfahren der Massivum-formung durch den Ringstauchversuch, Industrie Anzeiger, 15-20.

Christiansen, P., Hattel, J.H., Bay N., Martins P.A.F., 2013, Modelling of damage during hot forging of ingots, Proc. 5th Int. Conf. STEELSIM, Ostrava, 42-54.

Dziubińska, A., Gontarz, A., Dziubiński, M., Barszcz, M., 2016, The forming of magnesium alloys forgings for aircrafts and automotive applications, Advances in Science and Technology Research Journal, 10(31), 158-168.

Freudenthal, A.M., 1950, The inelastic behavior of engineering materials and structures, 1st ed., John Wiley & Sons Ltd., New York.

Gouveia, B.P.P.A., Rodrigues, J.M.C., Martins, P.A.F., 1996, Fracture criteria in bulk metal forming, International Journal of Mechanical Sciences, 38(4), 361-372.

Hilser, O., Rusz. S., Tanski. T., Snopinski. P., Dzugan. J., 2016, Krauss. M., Mechanical properties and structure of AZ61 magnesium alloy processed by equal channel angular pressing, Proc. 4th Int. Conf. Recent Trends in Structural Materials COMAT, Pilsen, 1-8.

Jain, M., Allin, J., Lloyd, D.J., 1999, Fracture limit prediction using ductile fracture criteria for forming of an automotive aluminum sheet, International Journal of Mechanical Sciences, 41, 1273–1288.

Jakubowski, K., Jakubowski, Ł., Sińczak, J., Skubisz, P., 2014, Patent No. PL 215668.
Korbel, A., 1986, Microscopic versus macroscopic aspects of shear bands deformation, Acta Metallurgica, 34(10), 1905-1909.

Kuczmaszewski, J., Zagorski, I., Dziubinska, A., 2014, Investigation of ignition temperature, time to ignition and chip morphology after the high-speed dry milling of magnesium alloys, Aircraft Engineering and Aerospace Technology, 88(3), 389-396.

Lisiecki, Ł., Skubisz, P., Karwan, J., 2015, Prediction and investigation of fracture initiation in warm forging of martensitic stainless steel with aid of FEM simulation, Computer Methods in Materials Science, 15, 246-352.

Lisiecki, Ł., Skubisz, P., 2015, Analysis of the impression-die forging process of hard-to-deformation magnesium alloys with regard to fracture occurrence, Rudy i Metale Nieżelazne Recykling, 60, 12, 664–668 (in Polish).

Mordike, B.L., Ebert, T., 2001, Magnesium: Properties – applications – potential, Materials Science and Engineering A, 302,37-45.

Pires, F.M.A., Cesar de Sa, J.M.A., Costa Sousa, L., Natal Jorge, R.M., 2003, Numerical modelling of ductile plastic damage in bulk metal forming, International Journal of Mechanical Sciences, 45, 273–294.

Skubisz, P., Sińczak, J, 2007, Precision forging of thin-walled parts of AZ31 magnesium alloy, Archives of Metallurgy and Materials, 52(2), 329-336.

Skubisz, P., 2007, Determination of bulk forming conditions for Mg-Al-Zn magnesium alloys in warm-forming temperatures, Ph.D. thesis, AGH University of Science and Technology, Kraków, (in Polish).

Swiostek, J., Göken, J., Letzig, D., Kainer, K.U., 2006, Materials Science and Engineering A, 424, 223-229.

Wagener, H.W., Wolf, J., 1994, Coefficient of friction in cold extrusion,
Journal of Material Processing Technology, 44, 283-29.

Yoshida, Y., Arai, K., Itoh, S., Kamado, S., Kojima, Y., 2005, Realization of high strength and high ductility for AZ61 magnesium alloy by severe warm working. Science and Technology of Advanced Materials 6, 185-194.