Hot compression behavior and deformation microstructure of Mg-6Zn-1Al-0.3Mn magnesium alloy
(Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China)
Abstract: The hot compression behavior of a wrought Mg-6Zn-1Al-0.3Mn magnesium alloy was investigated using Gleeble test at 200-400 °C with strain rates ranging from 0.01 to 7 s-1. The true stress—strain curves show that the hot deformation behavior significantly depends on the deformation temperature and strain rate. The calculated hot deformation activation energy Q is 166 kJ/mol with a stress exponent n=5.99, and the constitutive equation is deduced to be =3.16×1013[sinh(0.010σ)]5.99exp [-1.66×105/(RT)]· Deformation microstructure shows that the incompletely dynamically recrystallized grains can be found at grain boundaries and twins with the strain rates ranging from 0.01 to 1 s-1 at 250 °C, and completely dynamic recrystallization occurs when the temperature is 350 °C or above during hot compression, the size of recrystallized grains decreases with the increment of the strain rate at the same temperature. The relatively suitable deformation condition is considered temperature 330-400 °C and strain rate of 0.01-0.03 s-1, and temperature of 350 °C and strain rate of 1 s-1.
Key words: wrought magnesium alloy; hot compression; stress; strain; recrystallization