The fatigue endurance limit of a Zr-based bulk metallic glass

A stress–life study of a bulk metallic glass (Zr41.25Ti13.75Ni10Cu12.5Be22.5) using notched cylindrical bars reported a fatigue endurance limit of ∼1/2 of the ultimate tensile strength. This result is significantly higher than the value of ∼1/10 of the endurance limit previously reported using four-point bend specimens. A careful study of the stress state and final fracture surfaces for the notched specimens together with an error in the stress concentration factor employed in the original paper were found to explain the discrepancies.