This study deals with additive manufacturing (AM) products. Employing AM technology, complex-shaped, and lightweight parts can be fabricated using the aluminum alloy, AlSi10Mg. Typically, AM of this alloy is performed by laser powder bed fusion (LPBF). The mechanical properties of LPBF products are crucial for many engineering applications. Therefore, there have been efforts to measure the dynamic and quasi-static properties of such products. However, both the dynamic and quasi-static shear behaviors of this alloy are yet to be investigated. The present study is focused on experimentally investigating the shear behavior of LPBF AlSi10Mg. ‏Quasi-static shear tests were performed according to the ASTM B565 protocol, whereas dynamic shear tests were conducted using a standard split Hopkinson pressure bar equipped with an innovative sample holder that generates pure shear in a sample. The results of the performed tests showed that as the shear load rate increased, the shear strength considerably increased. In addition, in the quasi-static regime, the shear strength was practically independent of the product build direction. In contrast, under the dynamic shear conditions, samples built horizontally failed at a shear strength approximately 10% lower than that of those manufactured vertically. To investigate the build orientation effect on the shear behavior, this study conducted extensive microstructural characterization along with fracture analysis. Crack nucleation and propagation were analyzed in view of the effects of the unique microstructural characteristics of the LPBF AlSi10Mg, including the morphologies of the melt pool boundaries. The results obtained in this study suggested that for engineering applications in which dynamic loads are expected, the build orientation of AlSi10Mg parts produced using LPBF technology must be considered.

本研究涉及增材制造 (AM) 产品。采用 AM 技术，可以使用铝合金 AlSi10Mg 制造形状复杂且重量轻的零件。通常，这种合金的 AM 是通过激光粉末床融合 (LPBF) 进行的。LPBF 产品的机械性能对许多工程应用至关重要。因此，人们一直在努力测量此类产品的动态和准静态特性。然而，这种合金的动态和准静态剪切行为还有待研究。本研究的重点是通过实验研究 LPBF AlSi10Mg 的剪切行为。准静态剪切试验是根据 ASTM B565 协议进行的，而动态剪切测试是使用标准分体式霍普金森压力棒进行的，该压力棒配备了创新的样品架，可在样品中产生纯剪切。试验结果表明，随着剪切载荷速率的增加，剪切强度显着增加。此外，在准静态状态下，剪切强度实际上与产品构建方向无关。相比之下，在动态剪切条件下，水平制造的样品在剪切强度比垂直制造的样品低约 10% 时失败。为了研究构建方向对剪切行为的影响，本研究进行了广泛的微观结构表征和断裂分析。考虑到 LPBF AlSi10Mg 独特的微观结构特征的影响，包括熔池边界的形态，对裂纹成核和扩展进行了分析。本研究中获得的结果表明，对于预期动态载荷的工程应用，必须考虑使用 LPBF 技术生产的 AlSi10Mg 部件的构建方向。