Abstract The asymmetric mechanical response and corresponding statistical grain-scale slip/twinning activity for extruded Mg-(0~5 wt%)Y sheets during room-temperature uniaxial tension and compression along the extruded direction were investigated using slip trace analysis and EBSD-based misorientation analysis. The tension-compression asymmetry, in terms of yield strength, ultimate strength and uniform elongation, reduced with the addition of 0.5% Y to Mg. Increasing the Y concentration to 5% resulted in a reversed yield asymmetry (compressive yield strength > tensile yield strength). The non-basal slip activity increased (up to 31%) and the twinning activity decreased with increasing Y content, for both tension and compression. The Y-induced texture change did not significantly affect the pyramidal slip, while it promoted basal slip and suppressed prismatic slip. The observed trends of the slip activity suggested that the critical resolved shear stress (CRSS) ratios of CRSSpyramidal /CRSSbasal and CRSSpyramidal /CRSSprismatic decreased with Y addition. The correlation between macroscopic asymmetric behavior and slip/twinning activity implied that the pronounced pyramidal slip, together with the negligible twinning, were responsible for the reversed yield asymmetry. A higher activity of pyramidal slip was observed when the slip plane underwent tension compared with that for compression.

中文翻译：

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挤压 Mg-Y 片材中的拉伸 - 压缩不对称性和潜在的滑移/孪生活动

摘要 使用滑移迹分析和基于 EBSD 的方法研究了挤压 Mg-(0~5 wt%)Y 板在室温单轴拉伸和挤压过程中沿挤压方向的不对称力学响应和相应的统计晶粒尺度滑移/孪生活性。误判分析。在屈服强度、极限强度和均匀伸长率方面的拉压不对称性随着向 Mg 中添加 0.5% Y 而降低。将 Y 浓度增加到 5% 会导致反向屈服不对称（压缩屈服强度 > 拉伸屈服强度）。对于拉伸和压缩，非基底滑动活性增加（高达 31%），孪晶活性随着 Y 含量的增加而降低。Y 诱导的纹理变化对锥体滑移没有显着影响，促进基底滑移，抑制棱柱滑移。观察到的滑动活动趋势表明，CRSSpyramidal /CRSSbasal 和 CRSSpyramidal /CRSSprismatic 的临界分辨剪切应力 (CRSS) 比率随着 Y 的加入而降低。宏观不对称行为与滑移/孪生活动之间的相关性表明，明显的金字塔形滑移以及可忽略不计的孪生是反向屈服不对称的原因。与受压相比，当滑移面受拉时，锥体滑移的活性更高。宏观不对称行为与滑移/孪生活动之间的相关性表明，明显的金字塔形滑移以及可忽略不计的孪生是反向屈服不对称的原因。与受压相比，当滑移面受拉时，锥体滑移的活性更高。宏观不对称行为与滑移/孪生活动之间的相关性表明，明显的金字塔形滑移以及可忽略不计的孪生是反向屈服不对称的原因。与受压相比，当滑移面受拉时，锥体滑移的活性更高。