The surface roughness of components built using the laser powder bed fusion (L-PBF) process is poor. Surface finishing the internal channels of L-PBF components is a challenge. We propose a multi-jet hydrodynamic approach to enhance the surface finish quality of the internal channels. We investigate the hydrodynamic finishing on L-PBF Inconel 625 linear, stepped, and non-linear internal channels with diameters 5 to 1 mm and length up to 100 mm (replicating the geometries in rocket injectors, fuel nozzles, and cooling channels). The multi-jet hydrodynamic finishing approach improved the surface quality by 60–90 % (final Ra, Sa ≤ 1 μm and Rz, Sz ≤ 20 μm), using an abrasive concentration of ≤1 % in 15 min. of processing time. Areal surface texture parameters Sdr and roughness ratio r ≈1, evidenced the uniformity of the surface finish with dominant abrasive microcuts, regardless of the initial non-uniform additive manufactured surface. Most of the surface finished channels had excellent dimensional integrity and internal contour circularity. We then discussed the advancements required in metal additive manufacturing and internal surface finishing—to safely deploy L-PBF components with micro internal channels in fuel injection and fluid transfer applications.

使用激光粉末床熔化（L-PBF）工艺制造的组件的表面粗糙度很差。L-PBF组件内部通道的表面处理是一个挑战。我们提出了一种多喷头流体动力方法，以提高内部通道的表面光洁度。我们研究了L-PBF Inconel 625线性，阶梯和非线性内部通道（直径为5到1 mm，长度最大为100 mm）上的流体动力学精加工（复制了火箭喷射器，燃料喷嘴和冷却通道的几何形状）。该多喷射的流体动力精加工方法由60-90％（最终提高了表面质量镭，萨≤1微米和RZ，SZ ≤20微米）中，使用15分钟的≤1％的磨料浓度。处理时间。地域表面纹理参数Sdr和粗糙度比率[R ≈1，证明与主导磨料microcuts表面光洁度的均匀性，不管初始非均匀添加剂制造的表面。大多数表面精加工的通道具有出色的尺寸完整性和内部轮廓圆度。然后，我们讨论了金属增材制造和内部表面精加工所需的改进，以在燃料喷射和流体传输应用中安全地部署带有微内部通道的L-PBF组件。