In vitro corrosion properties and cytocompatibility of Fe-Ga alloys as potential biodegradable metallic materials

The in vitro biodegradable properties and cytocompatibility of Fe-Ga alloys including Fe₈₁Ga₁₉, (Fe₈₁Ga₁₉)₉₈B₂ and (Fe₈₁Ga₁₉)_99.5(TaC)_0.5, and pure Fe were investigated for biomedical applications. The microstructure of the alloys was characterized using X-ray diffraction spectroscopy and optical microscopy. The results showed that A2 and D0₃ phases were detected for the three types of Fe-Ga alloys, and additional Fe₂B and TaC phases were found in the (Fe₈₁Ga₁₉)₉₈B₂ and (Fe₈₁Ga₁₉)_99.5(TaC)_0.5 alloys, respectively. The corrosion rates of the Fe-Ga alloys were higher than that of pure Fe, as demonstrated by both potentiodynamic polarization measurements and immersion tests in simulated body fluid. The alloying element Ga lowered the corrosion potential of the Fe matrix and made it more susceptible to corrosion. Severe pitting corrosion developed on the surface of the Fe₈₁Ga₁₉ alloy after the addition of ternary B or TaC due to the multi-phase microstructures. The MC3T3-E1 cells exhibited good adhesion and proliferation behavior on the surfaces of the Fe-Ga alloys after culture for 4h and 24h.