Microstructure, Mechanical Properties and Corrosion Behavior of Biodegradable As-extruded Mg-2Zn-1Y-0.5Zr Alloys

Abstract:

The effects of extrusion temperature on dynamic recrystallization, texture and tensile properties of biodegradable Mg-2Zn-1Y-0.5Zr alloys were studied, and the corrosion mechanisms of as-extruded alloys in SBF solution were elaborated. The results show that the extruded alloy at 440 ℃ (E440) has a bimodal structure with coarse unrecrystallized (unDRXed) grains and fine recrystallized (DRXed) grains. The deformed grains from unDRXed region make the greatest contribution to the texture strength. The extruded alloy at 460 ℃ (E460) has uniform DRXed grains, and its excellent tensile properties reveal a dominance of fine grain strengthening. Simultaneously, the uniform DRXed grains are good for the weakening of texture strength. The E460 sample exhibits the best corrosion resistance with a corrosion rate of 0.669 ± 0.017 mm·a^-1.

Key words:biodegradable;extrusion;recrystallization;corrosion behavior