Prediction of flow stress of Mg−Nd−Zn−Zr alloy during hot compression
(1. National Engineering Research Center of Light Alloy Net Forming, Shanghai Jiao Tong University,
Shanghai 200240, China;
2. State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, Shanghai 200240, China)
Shanghai 200240, China;
2. State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, Shanghai 200240, China)
Abstract: Isothermal hot compression tests were carried out on Mg−3.0Nd−0.2Zn−0.4Zr (mass fraction, %, NZ30K) alloy using a Gleeble−3500 thermo-simulation machine at temperatures ranging from 350 to 500 °C and strain rates from 0.001 to 1 s−1. A correction of flow stress for deformation heating at a high strain rate was carried out. Based on the corrected data for deformation heating, a hyperbolic sine constitutive equation was established. The constants in the constitutive equation of the hyperbolic sine form were determined as a function of strain. The flow stresses predicted by the developed equation agree well with the experimental results, which confirms that the developed constitutive equations can be used to predict the flow stress of NZ30K alloy during hot deformation.
Key words: NZ30K alloy; magnesium alloy; constitutive equation; flow stress; isothermal compression