Microstructure Prediction by Finite Element Analysis during Hot Rolling of Magnesium Alloy Sheets

Abstract:

Material’s plastic deformation by hot forming processes can be used to make the materials generate dynamic recrystallization (DRX) and fine grains and accordingly products with more excellent mechanical properties, such as higher strength and larger elongation can be obtained. In this study, compression tests and water quenching are conducted to obtain the flow stress of the materials and the grain size after DRX. Through the regression analysis, prediction equations for the magnesium alloy microstructure were established. Simulations with different rolling parameters are conducted to find out the relationship between the DRX fractions or grain sizes of the rolled products and the rolling parameters. The simulation results show that rolling temperature of 400°C and thickness reduction of 50% are the optimal conditions. An average grain size of 0.204μm-0.206μm in the microstructure is obtained and the strength and formability of ZK60 magnesium alloys can be improved.

• Periodical: Key Engineering Materials (Volume 661)
• Pages: 105-112
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.661.105
• Online since: September 2015
• Authors: Yeong Maw Hwang, Tso Lun Yeh*
• Keywords: Dynamic Recrystallization, Grain Size, Hot Rolling

References

[1] Y. Z. Wu, H. G. Yan, S. Q. Zhu, J. H. Chen, A. M. Liu, X. L. Liu, Flow behavior and microstructure of ZK60 magnesium alloy compression at high strain rate, T. Nonferrous Met. Soc. China 24(2014) 930-939.

DOI: 10.1016/s1003-6326(14)63145-9

[2] B. L. Shi, T. J. Wang, J. Wang, Y. S. Yang, Hot compression behavior and deformation microstructure of Mg- 6Zn- 1Al- 0. 3Mn, T. Nonferrous Met. Soc. China 23(2013) 2560-2567.

DOI: 10.1016/s1003-6326(13)62768-5

[3] X. Wang, C. Yang, L. X. Hu, Mechanical properties and isothermal rolling process of AZ31 as-cast Mg alloy plate, Materials Science and Technology, Vol 19 No. 2 Apr, ( 2011).

[4] Y. D. Yu, H. X. Xi, Study on numerical simulation of extrusion forming for ZK60 magnesium alloys, Harbin University Of Science And Technology, Master Thesis (2009).

[5] M. Sellars, W. J. M. Tegart, "On the mechanism of hot deformation, Acta Metall., vol. 14, no. 9, (1966) p.1136–1138.

[6] Y. C. Lin, M. S. Chen, Numerical simulation and experimental verification of microstructure evolution in a three dimensional hot upsetting process [J]. J. Mater. Process Technol., 209(9): (2009) 4578−4583.

DOI: 10.1016/j.jmatprotec.2008.10.036

[7] C. Y. Sun, J. D. Luan, G. Liu, R. Li, Q. D. Zhang, Predicted constitutive modeling of hot deformation for AZ31 magnesium alloy, Acta Metall. Sin, 48(7) (2012) 853-860.

DOI: 10.3724/sp.j.1037.2011.00641

[8] C. M. Zener, J. H. Hollomon, Jr, Effect of strain rate upon plastic flow of steel. J. Appl. Phys., 15, 22 (1944).

DOI: 10.1063/1.1707363