Selective laser melting of an Mg/Metallic Glass hybrid for significantly improving chemical and mechanical performances

Abstract

Pure magnesium (Mg) is widely used as biomedical material, but its degradation rate is often too high and problematic to clinic applications. In this study, selective laser melting (SLM) was used to prepare an Fe-based metallic glass surface on a pure Mg substrate, forming a hybrid material to explore the advantage associated with such designed structure. It was found that the corrosion resistance was significantly improved with the hybrid material (from 0.89 ± 0.1 mm/a to 0.11 ± 0.03 mm/a in simulated body fluid), along with much increased hardness from 0.46 GPa to 14.3 GPa. The metallic glass surface was shown to retain its amorphous nature after the SLM processing. The molten pool formed by the applied laser beam resulted in a good mechanically interlocked bonding between the metallic glass layer and the Mg matrix. It was further revealed that the metallic glass surface had better wetting property than the Mg substrate, explaining why the MG-63 cells had good adhesion to it. The cell toxicity test was followed under the in vitro condition, indicating no toxicity in the metallic glass part. The results provide a feasible way to develop advanced Mg materials for biomedical applications via the capable SLM technology and via the suggested hybrid material.