In vitro degradation behavior and biocompatibility of Mg–5.8 Zn–2.0 Yb–0.5 Zr alloy during aging treatment

•Yb addition induces dense peak-aged nanoprecipitates promoting uniform corrosion.•The peak-aged alloy shows better long-term mechanical integrity in SBF solution.•ZK60–2Yb-T6 alloys exhibit good in vitro cytocompatibility and hemocompatibility.•The high-strength ZK60–2Yb alloy is suitable for the use of biodegradable implants. Ytterbium (Yb) containing magnesium alloys have aroused extensive interests because of their excellent mechanical properties. Unfortunately, their potential biomedical applications as a biodegradable implant material remain uncertain to date. In this study, in vitro degradation behavior and biocompatibility of the newly developed Mg–5.8 Zn–2.0 Yb–0.5 Zr (wt.%, denoted as ZYbK620) alloy during aging treatment were investigated. The results reveal that the dimension and distribution of Yb containing phases act a significant role in biocorrosion resistance and biocompatibility of ZYbK620 alloys. The peak-aged sample with much finer and denser nanoprecipitates possesses the lowest corrosion rate and best integrity after long-term immersion. Further biocompatibility testing demonstrates that the alloys with different aging times all exhibit favorable cytocompatibility and hemocompatibility, suggesting that the ZYbK620 alloy can be a promising candidate for biomedical applications.