Corrosion fatigue behavior of a Mg-based bulk metallic glass in a simulated physiological environment

Due to the superior property profile, Mg-based bulk metallic glasses (BMGs) are potential biodegradable biomaterials. Nevertheless, their corrosion fatigue behavior, which is essential for understanding the mechanical performance under joint actions of the cyclic loading and the aggressive human body environment, remains unexplored. In the present study, compression-compression fatigue experiments were conducted in air and in a simulated physiological environment to study the fatigue and corrosion fatigue behaviors of Mg₆₆Zn₃₀Ca₃Sr₁ BMG. The fatigue-endurance limits of Mg₆₆Zn₃₀Ca₃Sr₁ BMG in air and in the simulated physiological environment were 370 and 150 MPa, respectively, suggesting its qualified fatigue property for biomaterials and the detrimental effect of the corrosive environment on the fatigue resistance. During the fatigue tests, Mg₆₆Zn₃₀Ca₃Sr₁ BMG went through peeling-off fractures and then the final fragmented fracture. The corrosion in the simulated physiological environment, which provided easy crack-initiation sites for the peeling-off fractures and the final collapse, was responsible for the inferior fatigue resistance to that in air.