Fatigue behavior of a high-toughness Zr₆₁Ti₂Cu₂₅Al₁₂ bulk metallic glass

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The fatigue damage behavior of Zr₁₂Ti₂Cu₂₅Al₁₂ (ZT1) bulk metallic glass (BMG) was investigated based on the stress-life approach and the damage tolerance approach. The ZT1 exhibits the highest fatigue endurance limit among all monolithic BMGs, with a fatigue limit of σ_a=441 MPa under four-point-bending load, or ～0.27 of its tensile strength. The relation between the range of stress intensity factor (ΔK) and the crack-growth rate (da/dN) was also determined. ZT1 shows a fatigue threshold, ΔK_th, of 2.8 MPa√m, which appears to be related to its atomic topological structure.