Tailoring corrosion behavior and mechanical property of Mg-6Zn alloy with varying Dy contents for biological application

Abstract

The influence of alloying dysprosium (Dy) element on the biodegradable behavior and mechanical property of Mg-6Zn alloys in a simulated body solution (SBF) solution was studied. The results indicate that Dy significantly contributes to grain refinement, and form a distinctive fiber texture in Dy-containing alloys. The presence of Dy promotes the formation of granular DyZn₃ precipitates, which possess a higher electrode potential than the matrix, thus accelerating matrix corrosion. Corrosion results demonstrate that the Dy element is not beneficial to reducing the initial corrosion rate of Mg-6Zn but is conducive to improving the protective effect of product film as the immersion time increases. Dy-containing alloys exhibit higher strength than Mg-6Zn while maintaining good plasticity related to grain boundary and precipitation strength effects. Consequently, the incorporation of 2 wt.% Dy into Mg-6Zn alloys results in a synergistic enhancement of strength, as well as moderate corrosion resistance and fracture elongation.