Current percent-porosity based quantification of pores in additively manufactured parts does not provide information about the size, shape, and distribution of pores throughout a build. Such information is necessary to understand the conditions under which the part was printed as well as its mechanical reliability. This research, through a combination of fatigue testing and microstructural characterization demonstrates a method by which the internal porosity can be characterized and using the knowledge of the pores differing formation mechanisms to inform future design and build strategies. Though the test bars were printed under nominally identical conditions, ignoring lack-of-fusion, batch 1 had 34 pct fewer lenticular pores and 147 pct more spherical pores than batch 2 which shows that the actual print conditions of these parts varied substantially as would their as-printed mechanical reliability. To quantify this difference extensive optical, SEM, and EBSD metallographic studies were conducted on several samples from these bars as well as the fracture surfaces to gain an understanding of the porosity’s shape, size, and location. The comparison of these datasets along with knowledge of the pore’s evolution allows for the optimization of future build strategies and the more accurate prediction of the resulting as-built mechanical properties.

当前基于百分比孔隙率的增材制造零件中的孔定量无法提供有关整个构件中孔的大小，形状和分布的信息。这样的信息对于理解零件的印刷条件及其机械可靠性是必不可少的。这项研究通过疲劳测试和微观结构表征相结合，展示了一种可表征内部孔隙率的方法，并利用对孔隙形成机制不同的认识来为未来的设计和建造策略提供依据。尽管测试条是在名义上相同的条件下打印的，但忽略了融合不足的情况，批次1比批次2少了34％的透镜状孔和147％的球形孔，这表明这些零件的实际印刷条件与印刷时的机械可靠性大不相同。为了量化这种差异，对这些试棒以及断裂表面的几个样品进行了广泛的光学，SEM和EBSD金相研究，以了解孔隙的形状，大小和位置。这些数据集的比较以及对孔隙演化的了解可以优化未来的构建策略，并可以更准确地预测所生成的力学性能。EBSD金相研究是从这些试条以及断裂表面的几个样品上进行的，以了解孔隙的形状，大小和位置。这些数据集的比较以及对孔隙演化的了解可以优化未来的构建策略，并可以更准确地预测所生成的力学性能。EBSD金相研究是从这些试条以及断裂表面的几个样品上进行的，以了解孔隙的形状，大小和位置。这些数据集的比较以及对孔隙演化的了解可以优化未来的构建策略，并可以更准确地预测所生成的力学性能。