Additive manufacturing (AM), particularly Laser Powder Bed Fusion (PBF-LB/M), is revolutionizing the design of complex engineering components. This study investigates IN718 heat exchanger samples produced by PBF-LB/M, focusing on the interplay between internal geometry and AM-specific surface characteristics. A series of heat exchanger prototypes with varied channel geometries were developed to explore how geometric complexity influences manufacturability and surface quality. A key focus is the characterization of as-built surface roughness and its relation to design parameters such as channel shape, spiral diameter, and build orientation. Surface topographies in critical flow regions revealed systematic trends linked to laser exposure, powder adhesion, and local thermal gradients, especially in overhang and inclined surfaces. The study shows how additive manufacturing parameters and design choices affect surface characteristics and build quality of internal structures. By systematically varying geometries and orientations, design strategies are identified that promote successful fabrication while reducing the need for post-processing. The novelty of this work lies in establishing a direct link between surface roughness, channel fidelity, and hydraulic performance in LPBF-fabricated IN718 heat exchanger prototypes. These insights support the development of design guidelines for functional AM heat exchangers and lay the foundation for optimized manufacturability and future performance testing.
Acharya et al. (Thu,) studied this question.