Effect of long period stacking ordered structure on the biocorrosion resistance and osteogenesis ability of Mg–Zn–Y-Mn alloys

Microstructure, biocorrosion resistance, and osteogenesis performances of as-cast Mg-Zn-Y-Mn alloys with different volume fraction of long period stacking ordered (LPSO) structure are investigated. 18R-LPSO phase can be formed in Mg-1Zn-2Y-0.5Mn (ZWM120), Mg-2Zn-4Y-0.5Mn (ZWM240) and Mg-4Zn-8Y-0.5Mn (ZWM480) alloys, and their volume fraction increases with the elevating Zn and Y content. The micro-galvanic effect between cathodic LPSO and anodic α-Mg dominate the corrosion mechanism of the three alloys, resulting in the accelerating corrosion rate with the increasing volume fraction of LPSO phase in Hank’s solution. With least LPSO phase, ZWM120 exhibits best cytocompatibility and osteogenic differentiation ability in rat bone marrow stem cells, suggesting that few Zn and Y addition is more potential for orthopedic applications.