Part-agnostic ultrasonic melt pool vibration in wire-laser directed energy deposition

Ultrasonic vibration assistance has proven itself as a useful tool in homogenizing microstructures and improving structural properties in localized fusion processes (welding, additive manufacturing, etc.). Current implementations of vibration transmission are geometry-limited, requiring adjacent material to transmit oscillations. Next-generation additive manufacturing processes for large components and non-planar deposition require geometry-independent solutions for microstructural refinement. This study outlines a method of localized, part-agnostic melt pool vibration and preliminary results for the efficacy of improving structural outcomes. In-situ melt pool images confirm vibration transmission and cavitation within the molten material. Grain refinement with ultrasonic vibration corroborates previous literature on the microstructural outcomes with vibration assistance. The outlined methodology shows promise for unifying microstructures within large, multi-axis deposition strategies required in aerospace, agricultural, energy, and transportation sectors.