Comparison of Material Flow Stress Models toward More Realistic Simulations of Friction Stir Processes of Mg AZ31B


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Utilizing a proper material model for describing the mechanical behavior of any material is key for a successful simulation of friction stir processing (FSP) where temperature, strain, and strain rate gradients vary abruptly within, and when moving away, from the stirring zone. This work presents a comparison of how faithfully do three different constitutive equations reproduce the state variables of strain, strain rate, and temperature in an FEM simulation of a test-case FSP (1000 rpm spindle speed, and 90 mm/min feed). The three material models considered in this comparison are namely: Johnson-Cook (JC), Sellars-Tegart (ST), and Zerilli-Armstrong (ZA). Constants for these constitutive equations are obtained by fitting these equations to experimental mechanical behavior data collected under a range of strain rates and temperatures of twin-rolled cast wrought AZ31B sheets.It is widely recognized that JC-based models over predicts stress values in the stir zone whereas ST-based models are incapable of capturing work hardening outside of the stir zone. Therefore, a ZA model, being a physical based-HCP specific model, is hereby investigated for its suitability as a material model that would overcome such drawbacks of JC-and ST-based models. The equations from the constitutive models under consideration are fed into an FEM model built using DEFORM 3D to simulate the traverse phases of a friction stir process. Amongst these three material models, comparison results suggest that the HCP-specific ZA model yield better predictions of the state variables: strain, strain rate, and temperature, and, consequently, the estimated values for flow stresses.



Materials Science Forum (Volumes 783-786)

Main Theme:

Edited by:

B. Mishra, M. Ionescu and T. Chandra




A. H. Ammouri and R. F. Hamade, "Comparison of Material Flow Stress Models toward More Realistic Simulations of Friction Stir Processes of Mg AZ31B", Materials Science Forum, Vols. 783-786, pp. 2239-2243, 2014

Online since:

May 2014




* - Corresponding Author

[1] Azizieh, M., Kokabi, A. H., and Abachi, P., Effect of Rotational Speed and Probe Profile on Microstructure and Hardness of AZ31/Al 2O 3 Nanocomposites Fabricated by Friction Stir Processing, Materials and Design, 32/4 (2011) 2034-(2041).


[2] McNelly, T., Swaminathan, S., and Su, J., Recrystallization Mechanisms during Friction Stir Welding/Processing of Aluminum Alloys, Scr. Mater., (2008) 349-354.


[3] Chang, C., Lee, C., and Huang, J., Relationship Between Grain Size and Zener-Holloman Parameter During Friction Stir Processing in AZ31Mg Alloys, Scr. Mater., 51 (2004) 509-514.


[4] Aljoaba, S., Dillon Jr., O., Khraisheh, M., Jawahir, I. S., Modeling the Effects of Coolant Application in Friction Stir Processing on Material Microstructure Using 3D CFD Analysis, Journal of Materials Engineering and Performance 21. 7 (2012).


[5] Zhang, Z., and Zhang, H. W., Numerical studies on controlling of process parameters in friction stir welding, Journal of Materials Processing Technology, 209. 1 (2009) 241-270.


[6] Ammouri, A. H., Kheireddine, A. H., Hamade, R. F., Evaluating the Performance of Selected Constitutive Laws in the Modeling of Friction Stir Processing of AZ31B - Toward a More Sustainable Process, GCSM2013, The 11th Global Conference on Sustainable Manufacturing, Berlin, Germany (2013).


[7] Sellars, C., Tegart, W., Hot workability. International Materials Reviews, 17 (1972) 1-24.

[8] Johnson, GR., Cook, WH., A constitutive model and data for metals subjected to large strains, high strain rates and high temperatures, 21 (1983) 541-7.

[9] Zerilli, F.J., Dislocation mechanics-based constitutive equations, Metallurgical and Materials Transactions A, 35 (2004) 2547-55.

[10] McQueen, H. J., Myshlaev, M., Sauerborn, M., Mwembela, A., Flow Stress Microstructures and Modeling in Hot Extrusions of Magnesium Alloys, Magnesium Technology, The Minerals, Metals and Materials Society, (2000) 355-362.


[11] Rodriguez, A., Kridli, G., Ayoub, G., Zbib, H., Effects of the Strain Rate and Temperature on the Microstructural Evolution of Twin-Rolled Cast Wrought AZ31B Alloys Sheets, Journal of Materials Engineering and Performance (2013) 1-11.


[12] A. H. Ammouri, A. H. Kheireddine, G. Kridli, R. F. Hamade, 2012, Model-Based Optimization of Process Parameters in the Friction Stir Processing of Magnesium Alloy AZ31b with Active Cooling, The 10th Global Conference on Sustainable Manufacturing (IGCSM), Istanbul, Turkey, October 31, November 2, (2012).


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