To understand the effects of precipitate on the deformation mechanisms and plastic heterogeneity of a cast Mg–11Y-5Gd-2Zn-0.5Zr (wt.%) alloy, quantitative comparison studies were performed on the solid solution (T4) and peak-aged (T6) samples during room temperature compression based on slip trace analysis and electron backscatter diffraction (EBSD) analysis. At 10% plastic strain: no twins were observed in both T4 and T6 samples; the dominant slip mode transitioned from 2^nd order pyramidal <c+a> slip (34.1%) to basal <a> slip (50.5%) after the T6 treatment, which indicated that the precipitate-hardening effect for pyramidal slip was stronger than that for basal slip. Substantial active slip systems (up to 40%) exhibited low normalized Schmid factors (<0.1), implying that local stress deviated from the globally applied stress. Compared to the T4 sample, a larger magnitude of geometrically necessary dislocation (GND) density was found in the T6 sample, which indicated that the precipitates enhanced the plastic heterogeneity in terms of GND density. Most of the high GND density areas were near grain boundaries (GBs), but they also appeared in grain interiors. Almost every near-GB area with larger GND density tended to follow the conditions: (1) large orientation discrepancy between neighborhood grains; (2) at least one grain exhibiting slip traces; (3) the GB with the X phase. The GBs where slip transfer occurs tended to exhibit a homogeneous GND density distribution.

为了了解沉淀物对铸造Mg-11Y-5Gd-2Zn-0.5Zr（wt。％）合金的变形机理和塑性异质性的影响，对固溶体（T4）和峰时效（ T6）基于滑动轨迹分析和电子背散射衍射（EBSD）分析在室温下压缩的样品。在10％的塑性应变下：在T4和T6样品中均未观察到孪晶。主导滑移模式从^第二次过渡经T6处理后，锥体<c + a>滑移率（34.1％）达到基底<a>滑移率（50.5％），表明锥体滑移的沉淀硬化作用强于基底滑移。大量的主动滑移系统（高达40％）表现出较低的标准化Schmid因子（<0.1），这意味着局部应力偏离了全局施加的应力。与T4样品相比，在T6样品中发现了更大的几何必要位错（GND）密度，这表明沉淀物以GND密度的形式增强了塑性异质性。大部分高GND密度区域都靠近晶界（GB），但它们也出现在晶粒内部。几乎每个具有较高GND密度的近GB区域都趋于遵循以下条件：（1）相邻晶粒之间的取向差异较大；（2）至少一种具有滑移痕迹的谷物；（3）GB与X相。发生滑动转移的GB倾向于表现出均匀的GND密度分布。