Hot deformation of the extruded Mg–10Li–1Zn alloy: Constitutive analysis and processing maps

• Published in: Journal of alloys and compounds 2017-03, Vol.696, p.1269-1277
• Main Authors: Shalbafi, M., Roumina, R., Mahmudi, R.
• Format: Article
• Language: English
• Subjects: Alloys; Compacting; Compression tests; Constitutive model; Deformation; Deformation mechanisms; Dislocation mobility; Hot deformation; Magnesium base alloys; Microstructure; Processing maps; Stability; Strain; Strain rate; Yield strength
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2016.12.087

Hot deformation behavior of an extruded Mg–10Li–1Zn alloy (LZ101) was studied by compression testing in the temperature range of 523–723 K and strain rates of 0.001–0.1 s−1. The processing maps were developed for the samples deformed to strains of 0.25 and 0.55. These maps exhibit domains of safe regions in the temperature range of 648–698 K and 548–598 K and strain rates of 0.001–0.01 s−1 for the samples deformed to the strain of 0.25. The safe region for the samples deformed to the strain of 0.55 was, however, found to be in the temperature range of 548–598 K and strain rates of 0.001–0.01 s−1. According to the processing maps, instability regions were also identified to be in the temperature range of 523–573 K and strain rates of 0.01–0.1 s−1 for samples deformed to both strains of 0.25 and 0.55. Each domain was characterized by its corresponding microstructure. In addition, the flow stress of the Mg–10Li–1Zn alloy at elevated temperatures was modeled via an Arrhenius-type constitutive equation. The values of the power-law stress exponents in the range of 4.8–5.2, obtained from the Arrhenius-type model, indicate that the dominant mechanism during hot deformation of the Mg–10Li–1Zn alloy is dislocation climb. •Determine the optimum conditions for hot deformation of LZ101 alloy.•Microstructural characterization of safe and unsafe regions in processing maps.•Develop a new modeling analysis to predict the flow behavior of LZ101 alloy.•Dislocation climb is the dominant mechanism for hot deformation of LZ101 alloy.