Metal additive manufacturing is highly suited to enhance the performance of engineering applications with sophisticated internal features and passageways. Laser Powder Bed Fusion (LPBF) is commonly used or considered for fabrication in these applications, although the resulting channels can show significant form and surface deviations, particularly due to dross-formation at overhang-areas. Binder Jetting (BJ), another additive manufacturing method that can process metals does not employ a heat source to fuse powder particles during build-up and therefore has the potential to overcome these limitations. In this study, additively manufactured circular channels with a nominal diameter of two millimeters are made by LPBF and BJ in seven different directions and are extensively analyzed depending on their orientation. The test-artifacts are made by four different state-of-the-art LPBF and BJ system manufacturers with standard parameters in 17−4PH stainless steel and with similar layer thicknesses. A novel type of X-ray Computed Tomography (CT) image analysis method for additively manufactured channels is applied in combination with commercial image analysis software. Form deviations and surface texture are characterized in accordance with ISO1101 and ISO 4287:1997. Results show a high level of precision, independently of build direction for channels made by BJ when compared to LPBF. The accuracy of BJ-channels is strongly dependent on the appropriate scaling before printing. Parallel to the build direction, LPBF-channels exhibit superior characteristics. The channels investigated in this work are categorized into ISO tolerance grades IT13−17 for LPBF and IT13−15 for BJ following ISO268−2. Based on the findings, design considerations and characteristic attributes of each process to manufacture channels are discussed within a broader context.

金属增材制造非常适合通过复杂的内部特征和通道来增强工程应用的性能。激光粉末床熔合（LPBF）通常在这些应用中使用或考虑用于制造，尽管最终的通道可能显示出明显的形状和表面偏差，特别是由于悬垂区域的浮渣形成所致。粘合剂喷射（BJ）是可以加工金属的另一种增材制造方法，在积聚过程中不使用热源来熔化粉末颗粒，因此有可能克服这些限制。在这项研究中，LPBF和BJ在七个不同的方向上制造了标称直径为2毫米的增材制造圆形通道，并根据其方向进行了广泛的分析。测试工件由四个不同的最新LPBF和BJ系统制造商制成，它们的标准参数为17-4PH不锈钢，并且层厚相似。与商业图像分析软件结合使用了一种新型的用于累加制造通道的X射线计算机断层扫描（CT）图像分析方法。根据ISO1101和ISO 4287：1997表征形状偏差和表面纹理。结果表明，与LPBF相比，BJ制作的通道的构建方向无关紧要的高精度。BJ通道的精度在很大程度上取决于打印之前的适当缩放比例。平行于构建方向，LPBF通道具有出色的特性。遵循ISO268-2，针对LPBF的ISO公差等级分为ISO13-17，对于BJ的IT13-15分为ISO13-2。基于这些发现，在更广泛的范围内讨论了制造通道的每个过程的设计考虑因素和特征属性。