Evaluating different methods to measure porosity in fused filament fabricated metals

Metal additive manufacturing (AM) is an emerging technology for producing metallic parts, with metal fused filament fabrication (FFF) technique gaining attention due to its cost-effectiveness. In FFF, a filament composed of metal powder and polymeric binder is deposited layer by layer, followed by debinding and sintering to produce the final part. However, FFF parts often contain microstructural defects, with porosity being one of the most critical ones, as it significantly impacts material properties. Accurate porosity measurement is therefore essential for ensuring part quality. Various methods have been proposed to analyze the microstructure and measure the porosity of AM metals. This study investigates the application of X-ray computed tomography, scanning electron microscopy, and Archimedes density measurement for analyzing porosity in metal FFF parts. This paper also highlights the sensitivity and limitations of each method, providing insights into the challenges associated with the porosity analysis of AM metals especially those produced by FFF.