The microstructural origin of anisotropy in the yield stress and ultimate tensile strength of AlSi10Mg tensile specimens produced by laser powder bed fusion (LPBF) is revealed using a combination of micropillar compression tests and microstructure-based numerical simulations. Uniaxial tensile tests demonstrate that specimens with tensile axis parallel to the build direction (vertical specimen) exhibit a higher yield stress and ultimate tensile strength than those perpendicular to the build direction (horizontal specimen). Micropillar compression experiments and a microstructure-based crystal plasticity model together confirm that the anisotropy has its origin in an elongated Al-Si cellular network (nominally 0.7 µm × 1.4 µm with long axis aligned with the build direction) within individual grains. A multiscale microstructure-based model predicts the mechanical properties of LPBF AlSi10Mg tensile specimens by accounting for the hierarchical microstructural features across length scales, which include the Al-Si network, the crystallographic grain structure, and the differences in microstructure between melt pool interiors and melt pool boundaries. The multiscale model over-estimates the yield stress, but correctly predicts the ultimate tensile strength and the anisotropy in the flow strength of tensile specimens. The model is used to computationally predict new microstructures driven by composition and processing parameters for LPBF AlSi10Mg alloys with improved mechanical properties.

结合微柱压缩试验和基于微观结构的数值模拟，揭示了由激光粉末床熔融 (LPBF) 生产的 AlSi10Mg 拉伸试样的屈服应力和极限拉伸强度各向异性的微观结构起源。单轴拉伸试验表明，拉伸轴平行于构建方向的试样（垂直试样）比垂直于构建方向的试样（水平试样）表现出更高的屈服应力和极限拉伸强度。微柱压缩实验和基于微观结构的晶体塑性模型共同证实了各向异性起源于单个晶粒内的细长 Al-Si 蜂窝网络（名义上为 0.7 µm × 1.4 µm，长轴与构建方向对齐）。基于多尺度微观结构的模型通过考虑长度尺度上的分层微观结构特征来预测 LPBF AlSi10Mg 拉伸试样的机械性能，其中包括 Al-Si 网络、晶粒结构以及熔池内部和熔体之间的微观结构差异。池边界。多尺度模型高估了屈服应力，但正确预测了拉伸试样的极限拉伸强度和流动强度的各向异性。该模型用于计算预测由具有改进机械性能的 LPBF AlSi10Mg 合金的成分和加工参数驱动的新微观结构。其中包括 Al-Si 网络、晶体晶粒结构以及熔池内部和熔池边界之间的微观结构差异。多尺度模型高估了屈服应力，但正确预测了拉伸试样的极限拉伸强度和流动强度的各向异性。该模型用于计算预测由具有改进机械性能的 LPBF AlSi10Mg 合金的成分和加工参数驱动的新微观结构。其中包括 Al-Si 网络、晶体晶粒结构以及熔池内部和熔池边界之间的微观结构差异。多尺度模型高估了屈服应力，但正确预测了拉伸试样的极限拉伸强度和流动强度的各向异性。该模型用于计算预测由具有改进机械性能的 LPBF AlSi10Mg 合金的成分和加工参数驱动的新微观结构。