Development Of Fe-based Bulk Metallic Glasses As Potential Biomaterials

Fe-based bulk metallic glasses(BMGs) exhibit the unique advantage as one of the potential biomaterials due to not only excellent mechanical, biocompatibility, corrosion resistance and relatively high glass forming ability(GFA), but also low cost compared to Ti-based, Zr-based, Mg-based and Ca-based BMGs. In this thesis, we attempt to develop new Fe-based BMGs for biomedical implant application and the main work includes the following two parts.In the first part of work, Fe80-x-yCrxMoyP13C7(x=10, y=10 at.%; x=20, y=5 at.%;x=20, y=10 at.%) bulk metallic glasses with the maximum diameter of 6 mm have been prepared by combining method of fluxing treatment with J-quenching technique. Measured and studied the corrosion performance in both Hank’s solution(pH=7.4) and artificial saliva solution(pH=6.3) at 37 ?C by electrochemical measurements, the concentrations of metallic ions released and the biocompatibility in vitro test of NIH3T3 cells of the present Fe-based BMGs. The result indicates that the corrosion resistance of the present Fe-based BMGs in the above two simulated body solutions is much better than that of biomedical 316 L stainless steel(316L SS), and approaching that of Ti6Al4 V biomedical alloy(TC4); the concentrations of metallic ions released from the present Fe-based BMGs and TC4 are significant lower than that released from 316 L SS; the biocompatibility of the present Fe-based BMGs is better than 316 L ss and TC4. And the test result of the cell adhesion and growth on the surface of the samples indicates that the present Fe-based BMGs exhibit the better cell viability compared with 316 L SS and TC4 biomedical alloys. Form the present Fe-based BMGs, Fe55Cr20Mo5P13C7 BMG, exhibit an excellent performance.In the second part of work, in order to further improve the biomedical performance of Fe-based BMGs developed in the first part of work, Fe in Fe55Cr20Mo5P13C7 BMG(denoted as Co0) is partially substituted by Co. As a result, Fe45Co10Cr20Mo5P13C7(denoted as Co10) and Fe35Co20Cr20Mo5P13C7(denoted as Co20) BMGs are successfully prepared. The biomedical performance of Co0, Co10 and Co20 BMGs are characterized and studied following the same method as that in the first part of work, and so we can investigate the effect of the Co substitution for Fe on the biomedical performance of the present Fe-based BMG. The results indicate that the corrosion resistance in Hank’s solution of the present three BMGs successively decrease in the order of Co0, Co20 and Co10, while the order in the artificial saliva changes into Co20, Co0 and Co10. Further it is illustrated that the effect of Co-addition on the corrosion resistance of the present Fe-based BMGs is not obvious。 The biocompatibility of the present three BMGs becomes worse in the order of Co0, Co10 and Co20. It indicates that the Co addition degrade the biocompatibility of the present Fe-BMGs, which may be due to more biotoxicity of Co ion than that of Fe ion.