On the potential of Resonant Ultrasound Spectroscopy applied to the non-destructive characterization of the density of (LPBF) additively manufactured materials

The objective of the present work is to investigate the potential of Resonant Ultrasound Spectroscopy (RUS) as an innovative technique for the nondestructive analysis of Laser Powder Bed Fusion (LPBF) AlSi7Mg0.6 parts. The acoustic resonance measurements are tested against an experimental database that covers a broad range of process parameters and large variations of the standard volumetric energy density. Two other nondestructive techniques are used to assess the potential of the RUS measurements of additively manufactured samples: the easy-to-use Archimedes density measurement and the cost-intensive computerized X-ray tomography. Our results show that RUS provides both qualitative and quantitative insights that allow the detection of the amount of lack of fusion porosities and the estimation of the elastic properties of the fabricated samples. Quantitative correlations between the three nondestructive testing methods are obtained, hinting at how RUS could be used effectively for systematic post-production testing of LPBF samples.