Acoustically assisted additive manufacturing by laser powder-bed fusion of AlSi10Mg

Abstract

The exceptional design freedom offered by additive manufacturing, including the ability to create complex geometries and graded materials, along with its immense lightweight construction potential, are often cited as compelling advantages of the technology. However, these benefits are counterbalanced by challenges such as poor surface quality in the as-built state. Additionally, the formation of porosity, which has yet to be fully mitigated through parameter optimization, significantly diminishes cyclic strength, particularly when pores are located near the surface. Porosity also contributes to the high variability in physical properties, necessitating its reduction or complete elimination to ensure high reliability, consistent process performance, and long-term durability of the manufactured components. To address these issues, tailored sonication during the build process could offer multiple benefits for both the powder-bed and the emerging component. Initial prototypes and proofs of concept have been developed for Laser Metal Deposition (LMD) systems. However, the integration of an acoustic transducer into a Laser Powder-Bed Fusion (L-PBF) machine remains a challenge, posing numerous interdisciplinary questions in areas such as physical acoustics, mechanical engineering, materials science, and manufacturing technology. This study seeks to develop a functional acoustically assisted additive manufacturing system based on L-PBF. It focuses on designing an effective transducer, understanding the behavior of powder under acoustic excitation, and evaluating the resulting key properties of the manufactured parts.