缺口疲劳行为：金属玻璃与超高强度钢

Notch fatigue behavior: Metallic glass versus ultra-high strength steel.

作者信息

Wang X D, Qu R T, Wu S J, Duan Q Q, Liu Z Q, Zhu Z W, Zhang H F, Zhang Z F

机构信息

Shenyang National Laboratory for Materials Science, Institute of Metal Research Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, 110016, P.R. China.

出版信息

Sci Rep. 2016 Oct 18;6:35557. doi: 10.1038/srep35557.

DOI:10.1038/srep35557

PMID:27752136

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC5067664/

Abstract

Studying the effect of notch on the fatigue behavior of structural materials is of significance for the reliability and safety designing of engineering structural components. In this work, we conducted notch fatigue experiments of two high-strength materials, i.e. a TiZrNiCuBe metallic glass (MG) and a 00Ni18Co15Mo8Ti ultra-high strength steel (CM400 UHSS), and compared their notch fatigue behavior. Experimental results showed that although both the strength and plasticity of the MG were much lower than those of the UHSS, the fatigue endurance limit of the notched MG approached to that of the notched UHSS, and the fatigue ratio of the notched MG was even higher. This interesting finding can be attributed to the unique shear banding mechanism of MG. It was found that during fatigue process abundant shear bands formed ahead of the notch root and in the vicinity of the crack in the notched MG, while limited plastic deformation was observed in the notched UHSS. The present results may improve the understanding on the fatigue mechanisms of high-strength materials and offer new strategies for structural design and engineering application of MG components with geometrical discontinuities.

摘要

研究缺口对结构材料疲劳行为的影响对于工程结构部件的可靠性和安全设计具有重要意义。在本工作中，我们对两种高强度材料进行了缺口疲劳实验，即一种TiZrNiCuBe金属玻璃（MG）和一种00Ni18Co15Mo8Ti超高强度钢（CM400 UHSS），并比较了它们的缺口疲劳行为。实验结果表明，尽管MG的强度和塑性均远低于UHSS，但缺口MG的疲劳 endurance极限接近缺口UHSS的疲劳 endurance极限，且缺口MG的疲劳比甚至更高。这一有趣的发现可归因于MG独特的剪切带机制。研究发现，在疲劳过程中，缺口MG的缺口根部前方和裂纹附近形成了大量剪切带，而缺口UHSS中观察到的塑性变形有限。目前的结果可能会增进对高强度材料疲劳机制的理解，并为具有几何不连续性的MG部件的结构设计和工程应用提供新的策略。