Influence of Twinning Texture on the Corrosion Fatigue Behavior of Extruded Magnesium Alloys

Bio-magnesium alloys have received great attention due to their degradability and biocompatibility.Corrosion fatigue failure is a huge challenge in vivo for bio-magnesium alloy implants.Understanding the eff ects of twinning textures on the corrosion fatigue of magnesium alloys is meaningful for the applications.In the current study,pre-compression strains of 2%and 4%were carried out on extruded rods.The effects of twinning texture on the corrosion performance and corrosion fatigue resistance were investigated.The hydrogen evolution tests indicated that twinning texture enhanced the corrosion resistance of longitudinal cross section by improving uniformity of surface energy.The results of corrosion fatigue tests indicated that the differences in mechanical damage caused by twinning texture dominated the corrosion fatigue behavior under high stress amplitude.The secondary cracks of surface deteriorated the corrosion fatigue resistance of the original specimens under low stress amplitude.The compact corrosion film and the re-passivation of matrix suppressed the hydrogen induced cracking,thereby improving the corrosion fatigue resistance of the pre-compression specimens.