Acoustic levitation for additive manufacturing

Laser Powder Bed Fusion (LPBF) is an Additive Manufacturing (AM) process where a laser is used to sinter and fuse powder particles together on a baseplate which acts as a heatsink. This heat transfer results in undesirable residual stresses and potential part failure. A proposed method to study the process of sintering powder without a baseplate is acoustic levitation. A type of acoustic levitation uses a standing pressure wave generated between a set of transducers and a reflector to trap particles at the nodes of the wave. The purpose of this work is to leverage and optimize current standing wave levitation techniques to enable the levitation of metal powder for sintering, i.e., to achieve “bed-less” LPBF through acoustic levitation. Common acoustic levitators are limited to very small or low-density particles. Thus, the first step of this work was to create a simulation tool for the pressure field of an acoustic levitator. The program architecture prioritized input flexibility, including phase, voltage, frequency, number, and position of transducers. The program also outputs the lift capacity to facilitate the following stage of this project which will involve finding optimization solutions for the transducer inputs and acoustic levitator setup suitable for bed-less LPBF.