Effect of extrusion on the microstructure and corrosion behavior of Mg-Zn-Mn-(0, 1.5)Sr alloys in Hank’s solution

The microstructure, corrosion behavior, and cytocompatibility of as-cast and extruded Mg-Zn-Mn-(0, 1.5)Sr alloys in Hank’s solution are investigated. Grain refinement and preferred texture are confirmed after extrusion, while increase in dislocation density and fragmentation of Mg17Sr2 phases are the distinct features of Sr-free and Sr-containing alloys, respectively. Corrosion rate of Sr-free alloy is significantly accelerated by extrusion, while alloyed Sr eliminates this deterioration process. Alloying of Sr decreases the corrosion rate and enhances the cytocompatibility of the extruded Mg-Zn-Mn alloy without affecting the corrosion penetration depth, demonstrating the superiority of Sr alloying for the extruded magnesium alloy as implant materials. •Effect of Sr alloying and extrusion on corrosion of Mg-Zn-Mn alloy is investigated.•Corrosion rate of Sr-free alloy is accelerated but corrosion depth is decreased after extrusion.•Alloying Sr eliminates the deterioration process and decreases the corrosion rate of extruded alloy.•Counterbalanced effect of the microstructural changes dominates the corrosion behavior.•Superiority of alloyed Sr for the extruded Mg-Zn-Mn alloy is demonstrated.