Corrosion resistance and biocompatibility of graphene oxide coating on the surface of the additively manufactured NiTi alloy

Abstract

In recent years, selective laser melting (SLM)-NiTi alloy has attracted widespread interest due to its ability to prepare medical implant materials with complex shapes and high dimensional accuracy. However, SLM-NiTi biomedical materials still face the problems of Ni ion release, poor corrosion performance, and biological inertness. This study is the first to report that the preparation of graphene oxide (GO) coatings on the SLM-NiTi alloy via the electrodeposition method. By changing the deposition time, the effect on coating morphology, corrosion resistance, biomineralization, and biocompatibility was studied. The result showed that GO coating could effectively enhance the corrosion resistance of SLM-NiTi alloy and inhibit the Ni ions release. The GO coating obtained when the deposition time was 20 min possessed the best corrosion resistance, which corrosion current density was about two orders of magnitude lower than that of SLM-NiTi alloy. Moreover, GO coating can effectively promote the adhesion, growth, and proliferation of osteoblasts. Therefore, the GO coated SLM-NiTi alloy is promising for clinical application.