Effects of service stress on the deformation behavior and microstructures of Zn-0.5Mg-0.05Fe alloy from ambient to high temperatures

Abstract

To overcome challenges in the traditional melt casting process of zine alloys, such as oxidative burnout, compositional segregation, and grain coarsening, this study carried out hot compression deformation tests on Zn-0.5Mg-0.05Fe alloys prepared by powder metallurgy. The results show that increasing deformation temperature and decreasing strain rate reduce rheological stress. The hot compression deformation process exhibits three phases, as rheological stress increases, work hardening, dynamic softening, and steady-state fluidization are observed, respectively. An intrinsic equation for the hot compression process is derived as = 1.334 × 1010 × [sinh(0.0053σ)]7.62947exp(-109.931691/RT). Processing conditions for Zn-0.5Mg-0.05Fe alloy are determined from a processing map, suggesting that a safe zone of 25°C–130 °C deformation temperatures with 0.13s−1-0.36s−1 strain rates, and 120°C–200 °C deformation temperatures with 0.01s−1-0.6s−1 strain rates. Electron Back-scattering Patterns (EBSD) and Transmission Electron Microscope (TEM) results show both discontinuous dynamic recrystallization (DDRX) and continuous dynamic recrystallization (CDRX) during the hot deformation compression process. DRX reduces deformation resistance, refines the grains, and improves the mechanical properties of the alloys. This study provides theoretical insights and process guidance for preparing degradable zinc alloys with excellent mechanical properties.

Keywords

• Zn-Mg-Fe alloy
• Powder metallurgy
• Dynamic recrystallization mechanism
• Processing map
• Constitutive analysis