Corrosion–fatigue studies of the Zr-based Vitreloy 105 bulk metallic glass

The purpose of this study was to characterize the stress-life behavior of the Vitreloy 105 BMG alloy in the four-point bending configuration in a 0.6 M NaCl electrolyte. At high stress amplitudes, the corrosion–fatigue life was similar to the fatigue lives observed in air. The environment became increasingly detrimental with decreases in stress, and the corrosion–fatigue endurance limit decreased to about 50 MPa, an 88% decrease relative to testing in air. Similar to the tests conducted in air, oxide particles were found on the fracture surfaces but did not appear to significantly affect the corrosion–fatigue lives. However, wear and the resultant corrosion at the outer loading pins resulted in crack initiation in most of the samples. Thus, these results are considered conservative estimates of the corrosion–fatigue behavior of this BMG alloy. Monitoring of the samples and the open-circuit potentials revealed that the onset of significant crack growth occurred at an average of 92% of the total fatigue life. The mechanism of corrosion–fatigue degradation was found to be anodic dissolution.