Ultrasonic evaluation of elastic properties in laser powder bed fusion manufactured AlSi10Mg components

The complete stiffness matrices of different zones in laser powder bed fusion manufactured parts out of the aluminium alloy AlSi10Mg were analysed using Ultrasonic Phase Spectroscopy (UPS). With micro-computed tomography (mu CT), the complex pore architecture resulting from the layer-wise additive manufacturing was studied for two cases: a sample taken from the bulk as built hatching zone of a part and a sample representing the interface between the perimeter scan and hatching zone of a part. Five independent elastic constants describing transverse isotropic elastic anisotropy with respect to the building direction were determined by UPS and then correlated to the porosity description analysed via mu CT. Anisotropy was found especially for longitudinal wave propagation. In all cases, consistent and reproducible results are obtained. Finally, the influence of porosity on the elastic properties was described with a power-law approach and a good agreement is obtained.