Laboratory for Biomaterials and Bioengineering, Department of Mining, Metallurgical and Materials Engineering & University Hospital Research Center, Université Laval, Québec City, QC, Canada.
Acta Biomater. 2010 May;6(5):1726-35. doi: 10.1016/j.actbio.2010.01.010. Epub 2010 Jan 18.
An electroforming technique was developed for fabricating iron foils targeted for application as biodegradable cardiovascular stent material. The microstructure, mechanical properties and corrosion of electroformed iron (E-Fe) foils were evaluated and compared with those of pure iron made by casting and thermomechanical treatment (CTT-Fe), with 316L stainless steel (316L SS) and with other candidate metallic materials for biodegradable stents. Electron backscattered diffraction revealed an average grain size of 4 microm for E-Fe, resulting in a high yield (360 MPa) and ultimate tensile strength (423 MPa) being superior to those of other metallic biodegradable stent materials. Annealing at 550 degrees C was found to improve the ductility of the E-Fe from 8% to 18%. The corrosion rate of E-Fe in Hanks' solution, measured by potentiodynamic polarization, was higher than that of CTT-Fe, which had been found to have a slow in vivo degradation. The results showed that E-Fe possesses fine-grain microstructure, suitable mechanical properties and moderate corrosion rate as a degradable stent material.
开发了一种电铸技术来制造铁箔，目标是将其用作可生物降解心血管支架材料。评估了电铸铁（E-Fe）箔的微观结构、力学性能和腐蚀性能，并将其与铸造和热机械处理（CTT-Fe）的纯铁、316L 不锈钢（316L SS）以及其他可生物降解支架用候选金属材料进行了比较。电子背散射衍射显示 E-Fe 的平均晶粒尺寸为 4 微米，从而具有较高的屈服强度（360 MPa）和拉伸强度（423 MPa），优于其他可生物降解支架金属材料。在 550°C 退火发现可将 E-Fe 的延展性从 8%提高到 18%。通过动电位极化测量，在 Hank's 溶液中 E-Fe 的腐蚀速率高于 CTT-Fe，后者的体内降解速度较慢。结果表明，E-Fe 作为可降解支架材料具有细晶粒微观结构、合适的力学性能和适中的腐蚀速率。
