Experimental and Numerical Investigation of the Grain Size Evolvement of AZ31 Mg Alloy during High Ratio Extrusion

Abstract:

The grain size evolvement of AZ31 magnesium alloy during high ratio extrusion (HRE) was investigated by experiment and numerical simulation. A Yada model was established according to the results of experimental study and trial calculation. Effects of the deformation temperature, extrusion ratio and extrusion velocity on the grain size were analyzed. The results showed that the microstructure of the AZ31 alloy was dramatically refined by high ratio extrusion. The deformation conditions exhibited obvious effects on the grain size, and the deformation conditions were interplaying and interacting with each other during the HRE process. Compared to the deformation temperature and extrusion velocity, the severe plastic deformation induced by the high ratio extrusion is a major cause of grain refinement. With the increasing of the extrusion velocity, the grains could be refined due to a shorter recrystallized grain growth time. At the same time, the deformation temperature increased with the increasing of the plastic strain rate, which results in faster recrystallized grain growth. Finally, recommended method is advised to further refine the grain size.

• Periodical: Materials Science Forum (Volumes 747-748)
• Pages: 211-216
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.747-748.211
• Online since: February 2013
• Authors: Jin Bao Lin, Li Feng Ma, Yan Xia Chen, Chao Wang, Qing Xiang Liang, Xiao Chao Cui
• Keywords: AZ31 Magnesium Alloy, Grain Size Evolvement, High Ratio Extrusion, Yada Model

References

[1] Y. Kojima, Project of Platform Science and Technology for Advanced Magnesium Alloys, Materials Transactions. 42 (7) (2001) 1154-1159.

DOI: 10.2320/matertrans.42.1154

[2] J. Buha, Natural ageing in magnesium alloys and alloying with Ti, Journal of Materials Science. 43 (2008) 1220-1227.

DOI: 10.1007/s10853-007-2250-1

[3] X.S. Huang, K. Suzuki, A. Watazu, I. Shigematsu, N. Saito, Microstructure and texture of Mg-Al-Zn alloy processed by differential speed rolling, Journal of Alloys and Compounds. 457 (1-2) (2008) 408-412.

DOI: 10.1016/j.jallcom.2007.02.144

[4] J.B. Lin, Q.D. Wang, L.M. Peng, H.J. Roven, Microstructure and high tensile ductility of ZK60 magnesium alloy processed by cyclic extrusion and compression, Journal of Alloys and Compounds. 476 (1-2) (2009) 441-445.

DOI: 10.1016/j.jallcom.2008.09.031

[5] T. Mukai, M. Yamanoi, H. Watanabe, K. Higashi, Ductility enhancement in AZ31 magnesium alloy by controlling its grain structure, Scripta Materialia. 45 (2001) 89-94.

DOI: 10.1016/s1359-6462(01)00996-4

[6] J.B. Lin, Q.D. Wang, L.M. Peng, T. Peng, Effect of the cyclic extrusion and compression processing on microstructure and mechanical properties of as-extruded ZK60 magnesium alloy, Materials Transactions. 49 (5) (2008) 1021-1024.

DOI: 10.2320/matertrans.mc200766

[7] M. Mabuchi, H. Iwasaki, K. Yanase, K. Higashi, Low temperature superplasticity in an AZ91 magnesium alloy processed by ECAE, Scripta Materialia. 36 (1997) 681-686.

DOI: 10.1016/s1359-6462(96)00444-7

[8] M. Mabuchi, T. Asahina, H. Iwasaki, K. Higashi, Experimental investigation of superplastic behaviour in magnesium alloys, Materials Science and Technology. 13 (1997) 825-831.

DOI: 10.1179/mst.1997.13.10.825

[9] Y.J. Chen, Q.D. Wang, J.G. Peng, C.Q. Zhai, Improving the Mechanical Properties of AZ31 Mg Alloy by High Ratio Extrusion, Materials Science Forum. 503-504 (2006) 865-870.

DOI: 10.4028/www.scientific.net/msf.503-504.865

[10] R.Z. Valiev, R.K. IsIamgaliev, I.V. Alexandrov, Bulk nanostructured materials from severe plastic deformation, Progress in Materials Science. 45 (2000) 103-189.

DOI: 10.1016/s0079-6425(99)00007-9

[11] H.K. Lin, J.C. Huang, High Strain Rate and/or Low Temperature Superplasticity in AZ31 Mg Alloys Processed by Simple High-Ratio Extrusion Methods, Materials Transactions. 43 (2002) 2424-2432.

DOI: 10.2320/matertrans.43.2424

[12] Y.M. Hwang, M.T. Yang, Study of Hydrostatic Extrusion Processes with Extra-High Extrusion Ratio, Key Engineering Materials. 233-236 (2003) 311-316.

DOI: 10.4028/www.scientific.net/kem.233-236.311

[13] D. Shangli, T. Imai, S.W. Lim, N. Kanetake, N. Saitob, I. Shigematsu, Superplasticity in Mg–Li–Zn Alloys Processed by High Ratio Extrusion, Materials and Manufacturing Processes. 23 (4) (2008) 336-341.

DOI: 10.1080/10426910701860954

[14] Y.N. Wang, C.J. Lee, H.K. Lin, C.C. Huang, J.C. Huang, Influence from Extrusion Parameters on High Strain Rate and Low Temperature Superplasticity of AZ Series Mg Base Alloys, Materials Science Forum. 426-432 (2003) 2655-2660.

DOI: 10.4028/www.scientific.net/msf.426-432.2655

[15] C.C. Huang, J.C. Huang, I.K. Lin, Y.M. Hwang, Processing Fine-Grained and Superplastic AZ31 Mg Tubes for Hydroforming, Key Engineering Materials. 271-271 (2004) 289-294.

DOI: 10.4028/www.scientific.net/kem.274-276.289

[16] X.N. Wang, F.G. Li, Y.H. Liu, Simulation of the FGH96 Superalloy Microstructural Changes under Different Deformation Conditions, Materials Science Forum. 575-578 (2008) 455-461.

DOI: 10.4028/www.scientific.net/msf.575-578.455

[17] H. Yada, Proceedings of conference of metallurgists, M. B. Winnipeg, G. E. Ruddle, A. F. Crawley (Eds. ), CIM, Canada, 1987, p.105.