Fe-Zn supersaturated solid solution prepared by mechanical alloying and laser sintering to accelerate degradation

The slow degration of iron limits its bone implant application. The solid solution of Zn in Fe is expected to accelerate the degradation. In this work, mechanical alloying (MA) was used to prepare Fe-Zn powder with supersaturated solid solution. MA significantly decreased the lamellar spacing between particles, thus reducing the diffusion distance of solution atoms. Moreover, it caused a number of crystalline defects, which further promoted the solution diffusion. Subsequently, the MA-processed powder was consolidated into Fe-Zn part by laser sintering, which involved a partial melting/rapid solidification mechanism and retained the original supersaturated solid solution. Results proved that the Fe-Zn alloy became more susceptible with a lowered corrosion potential, and thereby an accelerated corrosion rate of (0.112±0.013) mm/year. Furthermore, it also exhibited favorable cell behavior. This work highlighted the advantage of MA combined with laser sintering for the preparation of Fe-Zn implant with improved degradation performance.