Abstract Austenitic Fe-Mn-C-based alloys are considered as promising candidates for biodegradable vascular implants due to their high strength, ductility and mechanical integrity during degradation. The present study demonstrates that microalloying with S and B is an effective method to further enhance the degradation rate and the mechanical properties of a Fe-30Mn-1C twinning-induced plasticity (TWIP) alloy without deteriorating the biocompatibility. For studying the microstructural changes due to S or B addition, the alloys were analysed by X-ray diffraction (XRD) as well as scanning electron microscopy (SEM) in combination with energy-dispersive X-ray spectroscopy (EDX), wavelength dispersive X-ray analysis (WDX) and electron backscatter diffraction (EBSD). Thereby precipitates of (Fe0.3Mn0.7)S and (Fe,Mn)23(C3B3) types were detected in the austenitic matrix. These precipitates have a distinct influence not only on the mechanical properties under tensile load but also on the occurring corrosion mechanism. This was displayed by potentiodynamic polarization measurements and immersion tests in simulated body fluid (SBF) and associated SEM as well as X-ray photoelectron spectroscopy (XPS) investigations. In vitro cytotoxicity analyses with L929 fibroblast cells indicated that microalloying with S and B does not affect the cytocompatibility. Thus, the novel alloy modifications show a high potential for future application as biodegradable implant material.

中文翻译：

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可生物降解的 Fe-30Mn-1C 的硫和硼微合金化 - 对微观结构、拉伸性能、体外降解和细胞毒性的影响

摘要 奥氏体 Fe-Mn-C 基合金由于其在降解过程中的高强度、延展性和机械完整性而被认为是可生物降解的血管植入物的有希望的候选材料。本研究表明，用 S 和 B 进行微合金化是进一步提高 Fe-30Mn-1C 孪晶诱导塑性 (TWIP) 合金的降解速率和机械性能而不降低生物相容性的有效方法。为了研究由于 S 或 B 添加引起的微观结构变化，通过 X 射线衍射 (XRD) 以及扫描电子显微镜 (SEM) 结合能量色散 X 射线光谱 (EDX)、波长色散 X射线分析 (WDX) 和电子背散射衍射 (EBSD)。从而沉淀出 (Fe0.3Mn0.7)S 和 (Fe, 在奥氏体基体中检测到 Mn)23(C3B3) 类型。这些沉淀物不仅对拉伸载荷下的机械性能有明显的影响，而且对发生的腐蚀机制也有明显的影响。这通过动电位极化测量和模拟体液 (SBF) 中的浸入测试和相关的 SEM 以及 X 射线光电子能谱 (XPS) 研究得到了证明。L929 成纤维细胞的体外细胞毒性分析表明，与 S 和 B 微合金化不会影响细胞相容性。因此，新型合金改性显示出作为可生物降解植入材料的未来应用的巨大潜力。这通过动电位极化测量和模拟体液 (SBF) 中的浸入测试和相关的 SEM 以及 X 射线光电子能谱 (XPS) 研究得到了证明。L929 成纤维细胞的体外细胞毒性分析表明，与 S 和 B 微合金化不会影响细胞相容性。因此，新型合金改性显示出作为可生物降解植入材料的未来应用的巨大潜力。这通过动电位极化测量和模拟体液 (SBF) 中的浸入测试和相关的 SEM 以及 X 射线光电子能谱 (XPS) 研究得到了证明。L929 成纤维细胞的体外细胞毒性分析表明，与 S 和 B 微合金化不会影响细胞相容性。因此，新型合金改性显示出作为可生物降解植入材料的未来应用的巨大潜力。