DYNA JOURNAL ENGINEERING

Key words:

process optimization, internal flow behavior, non-uniform material removal, additive manufacturing post-processing, polymer channel finishing, surface integrity, flow-induced wear, rheological modeling, channel geometry effects, pressure gradient analysis, micro-cutting mechanisms, manufacturing quality improvement

Article type:

ARTICULO DE INVESTIGACION / RESEARCH ARTICLE

Section:

RESEARCH ARTICLES

Additive manufacturing (AM) enables the fabrication of complex geometries, particularly internal channels with enhanced functional performance. Among AM techniques, fused deposition modeling (FDM) is widely used due to its design flexibility and cost-effectiveness; however, its layer-by-layer nature leads to high surface roughness, especially in hard-to-access geometries such as conformal cooling channels, adversely affecting flow behavior. In this study, a PLA-based conformal internal channel was produced via FDM and its internal surfaces were improved using abrasive flow machining (AFM). Unlike previous studies focusing on simplified geometries or metallic systems, this work investigates AFM performance on polymer-based FDM channels by combining experimental analysis with computational fluid dynamics (CFD) to clarify surface enhancement mechanisms. Surface quality was evaluated using roughness parameters (Ra, Rz), material removal rate (MRR), and surface profile analysis. Results show that Ra and Rz decreased from 3.08 µm to 0.63 µm and from 28.7 µm to 5.7 µm, corresponding to improvements of approximately 80% and 85%, with the most significant enhancement occurring during the initial cycles. CFD analysis revealed non-uniform pressure and wall shear stress distributions along the channel, explaining variations in material removal. A bidirectional AFM strategy improved surface uniformity. Overall, AFM is shown to be an effective post-processing method for enhancing surface quality in FDM-produced conformal channels. The findings also provide insight into flow-driven material removal mechanisms applicable to other layer-based AM systems with similar surface characteristics.
Key Words: additive manufacturing, fused deposition modeling, abrasive flow machining, conformal cooling channels, surface roughness, surface finishing, computational fluid dynamics, internal channel polishing, material removal rate, non-Newtonian flow, wall shear stress, post-processing techniques