Morphological analysis of FDM parts subjected to surface treatment

Fused Deposition Modeling (FDM) enables the fabrication of polymer components with complex geometries; however, poor surface finish and anisotropy limit their functional use. Existing post-processing methods often lack scalability or effectiveness. This study investigates three surface treatment techniques spray painting, acetone dipping, and copper sputtering-for improving the surface morphology of acrylonitrile butadiene styrene (ABS) parts produced by FDM. Samples were fabricated at a layer thickness of 0.254 mm and a nozzle temperature of 300 °C, and were subsequently characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and image-based surface analysis. The results demonstrate that spray painting provided the most significant enhancement, reducing surface roughness from ~ 22 μm to 6.5 μm and increasing hardness by 19%. Acetone dipping achieved partial surface smoothing but compromised dimensional accuracy, while copper sputtering produced uneven coatings because of restricted deposition uniformity. The findings highlight that spray painting offers a low-cost, practical, and scalable post-processing technique for improving the functional performance of FDM-produced ABS parts, making them more suitable for applications in prototyping and tooling.