机械合金化与激光烧结制备铁锌过饱和固溶体及其降解行为研究

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

过慢的降解限制铁的骨植入应用,锌固溶在铁基体中有望加速其降解。首先利用机械合金化制备铁锌过饱和固溶体粉末。在合金化过程中,机械力的作用使得粉末颗粒间反复焊合,减小了溶质原子扩散距离,同时出现大量晶格缺陷,进一步促进了溶质原子的扩散。随后,利用激光烧结技术把粉末固化成型,烧结过程中粉末部分熔化并快速凝固,从而维持了原有过饱和固溶体结构。实验结果表明,所制备铁锌合金的腐蚀电位降低,腐蚀速率提高到0.112 mm/year,且具有良好的生物相容性。这项工作展现了机械合金化与激光烧结组合工艺在制备高性能可降解铁锌植入物方面的巨大潜力。

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.