Hot Deformation Behavior and Workability of As-Cast Dilute Mg-1.2Zn-0.2Y Alloy
Flow stress behavior of as-cast dilute Mg-1.2Zn-0.2Y alloy was studied via uniaxial compression test at temperature (300–450°C) and strain rate (0.001–1 s−1) using a Gleeble-3500 thermal simulation tester. The constitutive equation with the deformation activation energy of 275.9 kJ/mol was established to describe the thermal deformation behavior of the tested material. The processing maps for the Mg alloy were also constructed based on dynamic material modeling. Optical microscopy, x-ray diffraction, transmission electron microscopy and electron backscatter diffraction were utilized to characterize the microstructures formed at elevated temperature. The results indicated that dynamic recovery was the dominant work-softening mechanism of the Mg-1.2Zn-0.2Y alloy at lower temperature and dynamic recrystallization mainly contributed to the deformation softening at higher temperature. The optimal processing parameters of the safe deformation window were identified as temperature of 420–450°C and strain rate of 0.001–0.01 s−1.
The authors acknowledge the financial support of the National Natural Science Foundation of China (Nos. 51574118, 51774124, 51574095) and Key Technologies R&D in Strategic Emerging Industries and Transformation in High-tech Achievements Program of Hunan Province, China (Grant No. 2016GK4056).
- 37.H. Mirzadeh, J. Mater. Res. 5, 1 (2016).Google Scholar
- 38.A. Rollett, F. Humphreys, G.S. Rohrer, and M. Hatherly, Recrystallization and Related Annealing Phenomena, 2nd ed. (Pergamon: Elsevier, 2004), pp. 219–224.Google Scholar
- 42.Y.V.R.K. Prasad, Indian J. Technol. 28, 435 (1990).Google Scholar