Microstructural evolution during fatigue is of significance for understanding the fatigue cracking of metallic alloys. Here, we visualized amorphization near the fatigue facets for an Mg-Gd-Y-Zn-Zr alloy with long-period stacking ordered (LPSO) phase upon very high cycle fatigue (VHCF). The small amorphous patches occurred in the relatively soft nano-Mg layers, compared to the hard LPSO phase, and the amorphous band propagated along with the basal plane near the LPSO/Mg interface. This should be intimately related to the local dislocation accumulation and cumulative damage upon the cycle loading-unloading.

中文翻译：

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循环变形过程中含LPSO镁合金纳米镁层的非晶化

疲劳过程中的微观结构演变对于理解金属合金的疲劳裂纹具有重要意义。在这里，我们对具有长周期堆叠有序 (LPSO) 相的 Mg-Gd-Y-Zn-Zr 合金在极高循环疲劳 (VHCF) 下疲劳面附近的非晶化进行了可视化。与硬质 LPSO 相相比，小非晶斑出现在相对较软的纳米镁层中，并且非晶带沿着 LPSO/Mg 界面附近的基面传播。这应该与循环装卸时的局部位错积累和累积损伤密切相关。