FeMnCSi alloy for degradable pin implants: Surface and in vitro characterization

Abstract

Biodegradable metals such iron-based materials, are studied as temporary implants in the orthopedic field due to their adequate mechanical properties, non-toxic degradation products, and the possibility of avoiding a second surgical intervention to remove the device. One strategy to overcome the slow degradation rate of pure Fe is the addition of alloying elements. The aim of this work is to characterize the in vitro behavior of a new FeMnCSi alloy (Fe 26.5Mn 0.5C 1.14Si 0.03P 0.01S), and compare it with the performance of pure iron in simulated body fluid. The alloy performance was characterized in terms of chemical composition, microstructure, hemocompatibility and electrochemical responseIt has been found that FeMnCSi alloy presented a marked and progressive degradation in simulated body fluid after 14 days of immersion, significantly larger than pure Fe. The presence of phosphate-based compounds was confirmed on the surface of the alloy after 1 day of immersion while only after 14 days of immersion was detected on Fe. Additionally, the FeMnCSi alloy demonstrates improved blood compatibility compared to pure iron, indicating its suitability for applications in irrigated areas such as bones.