Assessment Of Surface Roughness In Additively Manufactured Channels For Fluid Applications

Paper in proceeding, 2024

Metal additive manufacturing (AM) enables intricate designs, particularly beneficial for complex fluid applications in gas turbines. Despite its advantages, AM introduces higher surface roughness compared to conventional technologies. In the powder bed fusion–laser beam (PBF-LB) process, surface roughness elements can create blockages in small channels, leading to increased friction. Understanding how features like adhering powder particles, spatter, and melt tracks interact with fluid flow is essential for modeling friction in channel flows. This study statistically characterizes surface roughness variation, considering printing parameters and orientation, utilizing optical profilometers and microscopy. Test samples in stainless steel 316L include flat surfaces and channels oriented from 0° to 90° with 20° intervals. Adhering powder particles are primary inducers of channel roughness, exhibiting positive skewness and high slopes. The density of powder particles on flat surfaces is significantly lower. Therefore, other variables including melt tracks, printing direction, and power input, influence surface characteristics more.