Microstructure, mechanical properties and corrosion behavior of Fe-36.8Mn-6Si alloy prepared through low-temperature sintering via spark plasma sintering

Biodegradable iron (Fe)-based alloys represent a promising class of biomaterials due to their exceptional mechanical properties and biocompatibility. However, their clinical translation is hindered by slow degradation rates resulting from the formation of protective oxide layers. This study addresses this challenge by investigating Fe-36.8Mn-6Si alloy fabricated via mechanical alloying and spark plasma sintering (SPS) at low temperatures (650–750°C). The study systematically evaluates the effects of sintering temperature on microstructure, mechanical performance, and corrosion behavior in Hanks’ Balanced Salt Solution. Microstructural analysis reveals that elevated sintering temperatures enhance atomic diffusion, promoting densification through sintering neck growth and pore elimination. At 750°C, the alloy achieves a relative density above 98 % and exhibits optimal mechanical properties. Higher sintering temperatures reduce corrosion current density and mass loss rates of sintered alloys. Surface characterization after immersion reveals that lower-temperature sintered alloys develop thick, porous corrosion product layers rich in calcium phosphates and hydroxides, whereas higher-temperature specimens form sparse, localized deposits. This work underscores the potential of low-temperature SPS in engineering biodegradable metals with tailored microstructures for enhanced performance.