Corrosion mechanism and tribological behavior of biodegradable Zn-0.8Cu alloy fabricated by selective laser melting

Zn-0.8Cu alloys as biodegradable materials have been successfully fabricated by selective laser melting (SLM) methods. Characterization and properties tests have been conducted to investigate the effect of processing parameters on microstructure, in vitro degradation mechanisms and tribological behaviors. The results demonstrated that the corrosion resistance of the alloy decreased with increasing laser power and scanning speed during the SLM process. The optimal sample group (50W-250 mm/s) exhibited a corrosion rate of 38.70 ± 0.13 mm/a. The corrosion products were predominantly composed of Zn/Ca-based phosphates and other compounds, as confirmed by XRD and EDS analyses. The wear resistance of Zn-Cu alloy was evaluated under tribological conditions simulating physiological environments. The findings revealed that the anti-wear capability deteriorated with elevated laser power and scanning speed in SLM processing. The dominant wear mechanisms were identified as abrasive wear and adhesive wear, characterized by ploughing grooves and material transfer on worn surfaces. The optimal group (P5V2 sample) achieved an average coefficient of friction (COF) of 0.64 ± 0.05 and a wear rate of 1.18 ± 0.19 × 10 −4 mm 3 N −1 m −1 , indicating the superior tribological performance.