Abstract The assessment of the reliability of Bulk Metallic Glasses (BMGs) as structural materials needs further investigations, particularly dealing with the impact of the loading condition on the fatigue behavior. Stress ratio R is one of these important parameters associated with the fatigue loading. The present work investigates the high-cycle fatigue properties of Zr 55 Al 10 Ni 5 Cu 30 BMG at three distinct stress ratios from 0.1 to 0.7. Even though Part I of the present study has been mainly focused on the fatigue resistance considerations, a peculiar feature was found on the fracture surface at stress ratio of R = 0.7. Thus, this second part is investigating the fatigue crack propagation behavior of Zr 55 Al 10 Ni 5 Cu 30 BMG. Experimental results highlight a crack propagation behavior at R = 0.1 and 0.4 similar to the results reported in the research field. On the other hand, observations of fracture surface and tensile surface of specimens failed at high stress ratio of R = 0.7 underline a peculiar crack propagation behavior.

中文翻译：

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应力比对Zr 55 Al 10 Ni 5 Cu 30 块状金属玻璃疲劳行为的影响。第二部分——裂纹扩展机制的再确认和新发现

摘要 大块金属玻璃（BMGs）作为结构材料的可靠性评估需要进一步研究，特别是处理载荷条件对疲劳行为的影响。应力比 R 是与疲劳载荷相关的重要参数之一。目前的工作研究了 Zr 55 Al 10 Ni 5 Cu 30 BMG 在从 0.1 到 0.7 的三个不同应力比下的高周疲劳性能。尽管本研究的第一部分主要集中在疲劳抗力方面的考虑，但在应力比 R = 0.7 时在断裂表面上发现了一个特殊的特征。因此，这第二部分正在研究 Zr 55 Al 10 Ni 5 Cu 30 BMG 的疲劳裂纹扩展行为。实验结果突出了 R = 0.1 和 0 时的裂纹扩展行为。4 与研究领域报道的结果相似。另一方面，在 R = 0.7 的高应力比下，试样的断裂表面和拉伸表面的观察结果表明了一种特殊的裂纹扩展行为。