A comprehensive model to predict friction factors of fluid channels fabricated using laser powder bed fusion additive manufacturing

Abstract

Laser powder bed fusion (L-PBF), or selective laser melting, can be used to significantly reduce the size and weight of hydraulic components. However, the current design approach still greatly depends on the technician’s experience. The friction loss of the L-PBF fabricated fluid channels is greatly affected by the fabrication quality but remains unknown, which is essential for the design approach. In this study, circular 316L SS fluid channels with various diameters (4–10 mm) and build angles (0–90°) were fabricated using L-PBF. Fabrication quality was characterized, and the friction factors were measured and analyzed. The results indicate that the geometric tolerance and surface roughness are closely related to the build angle. The friction factor of the L-PBF fabricated channels, which is higher than the classical theory in the turbulent flow, is influenced by both channel diameters and build angles. A comprehensive model is developed to predict friction factors of the L-PBF fabricated fluid channels. Design guidelines of fluid channels are proposed, for the first time, by considering both fabrication quality and friction factors. • The influence of build angle on channel forming quality is studied. • The relationship between forming quality and friction factor is developed. • A comprehensive friction factor prediction model for 316L SS L-PBF channel is developed. • Design guidelines of L-PBF fabricated fluid channels are proposed.