Document Type : Research Paper


Department of Production Engineering and Metallurgy, University of Technology, Baghdad-Iraq


In this work, the cyclic expansion extrusion (CEE) process was applied to ZK60 Mg alloy. The correlation between the evolved microstructure and mechanical properties was investigated. The CEE process was performed at a constant ram speed (15 mm/min) and at different processing temperatures (190, 270, and 350 °C). Optical and scanning electron microscopes, X-ray diffraction instruments, Vickers hardness tester, and tensile testing machine were utilized to examine the influence of CEE processing temperature on the characteristics of ZK60 Mg alloy. The XRD analysis showed that two phases were presented in the matrix of ZK60 Mg alloy, namely α-Mg and MgZn2, in small amounts. The CEE process reduced the size of α-Mg grains due to dynamic recrystallization, especially at the processing temperature of 190 °C. A slight coarsening of the α-Mg grains was observed with increasing processing temperature to 270 and 350 °C. The hardness value ​​of ZK60 Mg alloy was enhanced by about 11 to 19% using the CEE process compared to the as-extruded sample. The processing temperature greatly affected the mechanical properties, where a significant improvement of about 24% yield strength, 9% ultimate tensile strength, and 38% elongation was observed using a processing temperature of 190 °C. The characterization of the tensile fracture surface of the tested samples indicated that the ductile-brittle fracture mode was responsible for the failure.

Graphical Abstract


  • · The cyclic expansion extrusion (CEE) process was applied to the ZK60 Mg alloy, and the influence of processing temperature was investigated.
  • · The CEE process at a processing temperature of 190 ºC showed significant refining of α-Mg grains to a size of approximately 9 μm.
  • · The mechanical properties of ZK60 Mg alloy were greatly affected by the CEE processing temperature.
  •  The tensile test fracture morphologies of unprocessed and CEEed ZK60 Mg alloy revealed the combination of ductile and brittle fracture mechanisms.


Main Subjects

J. Tan, S. Ramakrishna, "Applications of magnesium and its alloys: A review", Appl. Sci. 11 (2021) 6861. app11156861
[2] J.F. Nie, K.S. Shin, Z.R. Zeng, Microstructure, deformation, and property of wrought magnesium alloys, Metall. Mater. Trans. A 51 (2020) 6045–6109.
[3] Z.T. Madhloom, A.R. Ismail, Superplastic behavior of AZ31B magnesium alloy processed by equal channel angular pressing (ECAP), Eng. & Tech. J. 32 (2014) 1958-1970.
[4] A.R. Ismail, E.A. Hussein, Effect of differential speed rolling temperature into mechanical properties of AZ31B magnesium alloy, Eng. & Tech. J. 34 (2016) 1-11.
[5] J. Fu, S. Chen, Microstructure evolution and mechanical properties of as-cast and as-compressed ZM6 magnesium alloys during the two-stage aging treatment process, Mater. 14 (2021) 7760. ma14247760
[6] J. Bohlen, S. Meyer, B. Wiese, B.J.C. Luthringer-Feyerabend, R. Willumeit-Römer, D. Letzig, Alloying and processing effects on the microstructure, mechanical properties, and degradation behavior of extruded magnesium alloys containing calcium, cerium, or silver, Mater. 13 (2020) 391.
[7] S.K. Mohapatra, V. Ranjan, S. Tripathy, Study of severe plastic deformations of metallic materials: A move towards Amorphization, Mater. Today: Proc. 56 (2022) 735-741.
[8] M.Y. Zhan, W.W. Zhang, D.T. Zhang, Production of Mg-Al-Zn magnesium alloy sheets with ultrafine-grain microstructure by accumulative roll-bonding, Trans. Nonferrous Met. Soc. China 21(2011) 991-997.
[9] F. Lu, A. Ma, J. Jiang, J. Chen, D. Song, Y. Yuan, J. Chen, D. Yang, Enhanced mechanical properties and rolling formability of fine-grained Mg–Gd–Zn–Zr alloy produced by equal-channel angular pressing, J. Alloys Compd. 643 (2015) 28-33.
[10] Y.G. Ko, K. Hamad, Structural features and mechanical properties of AZ31 Mg alloy warm-deformed by differential speed rolling. J. Alloys Compd. 744 (2018) 96-103.
[11] B. Sulkowski, M. Janoska, G. Boczkal, R. Chulist, M. Mroczkowski, P. Palka, The effect of severe plastic deformation on the Mg properties after CEC deformation, J. Magnes. Alloy 8(2020) 761-768.
[12] Y. Li, J. Wang, R. Xu, The microstructure and mechanical properties of nanocrystalline Mg-Zn-Y alloy achieved by a combination of aging and high pressure torsion, Vacuum 178 (2020) 109396.
[13] S. Ahmadi, V. Alimirzaloo, G. Faraji, A. Doniavi, Properties inhomogeneity of AM60 magnesium alloy processed by cyclic extrusion compression angular pressing followed by extrusion, Trans. Nonferrous Met. Soc. China 31 (2021) 655-665.
[14] N. Pardis, B. Talebanpour, R. Ebrahimi, S. Zomorodian, Cyclic expansion-extrusion (CEE): A modified counterpart of cyclic extrusion-compression (CEC), Mater. Sci. Eng., A 528 (2011) 7537-7540.
[15] A.M. Marheb, A.D. Subhi, Enhancing the characteristics of ZK60 Mg alloy using cyclic expansion- extrusion (CEE) process, Accepted in: 2nd International Conference on Engineering and Advanced Technology, AIP Conf. Proc., 2022.
[16] S. Amani, G. Faraji, K. Abrinia, Microstructure and hardness inhomogeneity of fine-grained AM60 magnesium alloy subjected to cyclic expansion extrusion (CEE), J. Manuf. Process. 28 (2017) 197-208.
[17] S. Amani, G. Faraji, Recrystallization and mechanical properties of WE43 magnesium alloy processed via cyclic expansion extrusion, Int. J. Miner. Metall. Mater. 25 (2018) 672-681.
[18] V. Babu, B.P. Shanmugavel, K.A. Padmanabhan, On the microstructural homogeneity and mechanical properties of Al 6063 alloy processed by the cyclic expansion extrusion process, J. Mater. Eng. Perform. 29 (2020) 6870-6880.
[19] A. Siahsarani, F. Samadpour, M.H. Mortazavi, G. Faraji, Microstructural, mechanical and corrosion properties of AZ91 magnesium alloy processed by a severe plastic deformation method of hydrostatic cyclic expansion extrusion, Met. Mater. Int. (2020).
[20] C.J. Ma, M. Liu, G.H. Wu, W.J. Ding, Y.P. Zhu, Microstructure and mechanical properties of extruded ZK60 magnesium alloy containing rare earth, Mater. Sci. Technol. 20 (2004) 1661-1665.
[21] H.T. Jeong, W.J. Kim, Critical review of superplastic magnesium alloys with emphasis on tensile elongation behavior and deformation mechanisms, J. Magnes. Alloy (2022).
[22] H. Zhang, Z. Xu, S. Yarmolenko, L.J. Kecskes, J. Sankar, Evolution of microstructure and mechanical properties of Mg-6Al alloy processed by differential speed rolling upon post-annealing treatment, Metals 11 (2021) 926.
[23] R. Peng, C. Xu, Y. Li, S. Zhong, X. Cao, Y. Ding, Multiple-twinning induced recrystallization and texture optimization in a differential-temperature-rolled AZ31B magnesium alloy with excellent ductility, Mater. Res. Lett. 10 (2022) 318-326.
[24] K. Huang, J. Yao, Q. Hu, L. Shao, Z. Sun, Temperature effect on dislocation slip mechanism of nanotwinned Mg with void defect at the twin boundary, IOP Conf. Series: Materials Science and Engineering 484 (2019) 012018.
[25] H. Zhang, J. Zheng, Y. Shi, J. Ji, J. Zhang, Z. Zhang, Y. Xue, Microstructure and mechanical properties of pure magnesium prepared by CEE-AEC at different temperatures, Mater. Res. Express 8 (2021) 066511.
[26] C. W. Su, L. Lu, M. O. Lai, Mechanical behaviour and texture of annealed AZ31 Mg alloy deformed by ECAP, Mater. Sci. Technol. 23 (2007) 290-296.
[27] P.C. Gautam, S. Biswas, Effect of ECAP temperature on the microstructure, texture evolution and mechanical properties of pure magnesium, Mater. Today: Proc.  44 (2021) 2914-2918.
[28] L.B. Tong, J.H. Chu, W.T. Sun. Z.H. Jiang, D.N. Zou, S.F. Liu, S. Kamado, M.Y. Zheng, Development of a high-strength Mg alloy with superior ductility through a unique texture modification from equal channel angular pressing, J. Magnes. Alloy 9 (2021) 1007-1018.