High-cycle fatigue testing on AM60 magnesium alloy samples for as-received and pre-corroded conditions in simulated body fluid

Abstract

In this present work, the pure fatigue (PF) behaviors of AM60 magnesium alloys were investigated for the as-received samples, compared to the pre-corroded specimens in simulated body fluid (SBF). The standard fatigue testing specimens were held for 28 days in the SBF, so-called corrosion fatigue (CF) samples, while their weights were recorded. Afterward, bending fatigue experiments were carried out under fully-reversed rotary conditions, within high-cycle fatigue regimes. Moreover, the fracture mechanism was also investigated using field-emission scanning electron microscopy (FE-SEM). The obtained results indicated that the weight of the samples first increased and then decreased with time. The CF lifetime was 71 % of the relative difference, shorter than PF under the lowest stress level (80 MPa) and 38 % of the relative difference, shorter than PF at the highest stress level (140 MPa). The CF lifetime was entirely behind the PF lifetime, and fracture mechanisms were mostly brittle.