Effect of microstructure on small fatigue crack initiation and early propagation behavior in Mg-10Gd-3Y-0.3Zr alloy
Effect of microstructure on small fatigue crack initiation and early propagation behavior in Mg-10Gd-3Y-0.3Zr alloy
复制标题
微观组织对Mg-10Gd-3Y-0.3Zr合金细小疲劳裂纹萌生和早期扩展行为的影响
DOI：
10.1016/j.ijfatigue.2018.10.002
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发表时间：
2019-02-01
影响因子：
6
通讯作者：
Wang, Qingyuan
中科院分区：
文献类型：
--
作者：
He, Chao;Wu, Yujuan;Wang, Qingyuan
研究了一种含稀土镁合金（Mg-Gd-Y-Zr）的微观组织循环变形机制及其与疲劳小裂纹萌生和早期扩展行为的关系。结果表明，基体滑移是主要的变形机制，尤其是在粗晶区，并最终导致疲劳裂纹萌生。早期裂纹扩展行为的强烈影响，在晶粒尺寸和取向的局部微观结构的不均匀性。讨论了三种不同的显微组织-有利取向的粗晶、细晶团和不均匀取向的粗晶-的变形机制和抗裂纹扩展能力。这些微观结构的影响引起高度可变的裂纹扩展速率内的第一个类似于200 μ m的裂纹。
Microstructural cyclic deformation mechanisms and their relation to small fatigue crack initiation and early propagation behavior were experimentally investigated in a rare earth-containing magnesium alloy (Mg-Gd-Y-Zr). The results indicate that basal slip is the dominant deformation mechanism, especially in coarse grains, and eventually leads to fatigue crack initiation. Early crack propagation behavior was strongly influenced by local microstructural heterogeneities in grain size and orientation. Three kinds of microstructures-favorably-oriented coarse grains, fine grain clusters and unfavorably-oriented coarse grains-are discussed in terms of their deformation mechanisms and resistance to crack propagation. These microstructural effects caused highly variable crack propagation rates within the first similar to 200 mu m of cracks.