In the present study, the deformation mechanisms in a pure Mg single crystal deformed under the Erichsen test were investigated. The specimens were deformed for different punch strokes under a given crystallographic orientation relationship with respect to the punch direction at room temperature (RT). The electron backscattered diffraction (EBSD) technique was used for the microstructural study of the deformed specimens. The analysis showed that thin twin bands (TBs), consisting of several twin variants, were heterogeneously generated throughout the specimens. In particular, the specimen with the highest Erichsen Index (IE) value of 6.8 mm showed the most significant twinning activity throughout the thickness. The high stretch formability in the given crystallographic orientation is achieved due to the significant tensile twinning activity, which generates a favorable crystal orientation for the activation of basal slip under subsequent deformation. Furthermore, the crystal plasticity finite element method (CPFEM) was used to elucidate the heterogeneity observed during the experimental analysis by studying the strain component generated, the relative activity of different deformation modes, and the accumulated volume fraction of different twinning variants.

中文翻译：

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埃里克森试验下纯 Mg 单晶的变形机理：实验观察和晶体塑性预测


在本研究中，研究了在 Erichsen 试验下变形的纯 Mg 单晶的变形机制。在室温 （RT） 下，在给定的晶体取向关系下，试样相对于冲头方向发生不同冲程的变形。电子背散射衍射 （EBSD） 技术用于变形样品的微观结构研究。分析表明，由几个孪生变体组成的薄双条带 （TB） 在整个标本中异质生成。特别是，埃里克森指数 （IE） 值最高 6.8 mm 的试样在整个厚度上显示出最显着的孪生活性。由于显着的拉伸孪生活性，在给定的晶体取向中实现了高拉伸成型性，这为在随后的变形下激活基底滑移产生了有利的晶体取向。此外，通过研究产生的应变分量、不同变形模式的相对活性以及不同孪生变体的累积体积分数，采用晶体塑性有限元法 （CPFEM） 阐明了在实验分析过程中观察到的异质性。