A novel iron/zinc phosphate layered composite coating on Zn-0.5Li alloy for guided bone regeneration membrane applications
Chang Chen, Zhengqin Shi, Yanfang Deng, Xin Chu, Jun Cheng, Yixuan He, Yilong Dai
Abstract
Zinc (Zn) alloys currently demonstrate great potential and advantages as new biodegradable metal materials for guided bone/tissue regeneration (GBR/GTR) membranes. However, the uneven corrosion of Zn alloys and the release of excess Zn 2+ during degradation result in local cytotoxicity, limiting their practical applications. In this study, filtered cathode vacuum arc (FCVA) technology and chemical methods were utilized to fabricate a layered composite coating of iron (Fe)/phosphate zinc (ZnP) on the surface of a Zn-0.5 wt%Li alloy. The microstructure, bonding strength, water contact angle, tribological properties, corrosion resistance, and biocompatibility of the coated samples were comprehensively investigated. The results demonstrate that the Fe/ZnP layered composite coating exhibits a uniform and dense flower-like morphology on the surface with approximately 7% higher bonding strength (68.91 MPa) compared to single ZnP coating directly applied to the Zn–Li alloy substrate. Furthermore, the Fe/ZnP composite coating sample demonstrates superior wear resistance and corrosion resistance (1.72 μm/year) when compared to the Zn–Li alloy substrate; additionally, it induces a shift in corrosion mechanism from local corrosion to uniform corrosion. Furthermore, the Fe/ZnP composite coating sample showed better cell viability than the substrate material. Moreover, the hemolysis rate of the coating sample was 0.175%, indicating that it also has excellent blood compatibility. These findings indicate that the Fe/ZnP composite coating effectively mitigates uneven corrosion in Zn–Li alloy while enhancing its biocompatibility—suggesting potential applications in future bone implant materials.