Effect of Selective Laser Melting on Microstructure, Mechanical, and Corrosion Properties of Biodegradable FeMnCS for Implant Applications
Julia Hufenbach, J. Sander, Fabian Kochta, Stefan Pilz, Andrea Voß, U. Kühn, A. Gebert
Abstract
Selective laser melting (SLM) of biodegradable metallic materials offers a great potential for manufacturing customized implants. Herein, SLM processing of a novel Fe–30Mn–1C–0.02S twinning‐induced plasticity (TWIP) alloy and the resulting structural, mechanical, and corrosion properties are presented. The occurring rapid solidification results in a fine‐grained austenitic microstructure with mainly homogeneous element distribution, which is investigated by scanning electron microscopy (SEM) combined with energy‐dispersive X‐ray spectroscopy (EDX) and electron backscatter diffraction (EBSD) as well as X‐ray diffraction (XRD). By processing the alloy via SLM, significantly higher strengths under tensile and compressive load in comparison with those for the as‐cast counterpart and a 316L reference steel are achieved. Electrochemical corrosion tests in a simulated body fluid (SBF) indicate a moderate corrosion activity, and a beneficial uniform degradation is shown in immersion tests in SBF. Regarding the envisaged application for vascular implants, SLM‐processed stent prototypes out of the novel alloy are presented and a first functionality test is shown.