This study uses synchrotron-based X-ray imaging to investigate the dynamic keyhole oscillation in Ti-6Al-4V during laser melting with a high-frequency oscillating beam. The experimental observations are validated against simulations using a Lattice Boltzmann multiphysics model. The research reveals the continuous and periodic fluctuations in keyhole parameters unique to oscillating laser beam processing, responsible for chevron pattern formation. Despite inherent longer-range fluctuations, the technique shows potential for reducing keyhole instability, mitigating porosity, and altering surface topology, providing insights for future applications.

Ziheng Wu, Guannan Tang, Samuel J. Clark, Andrey Meshkov, Subhrajit Roychowdhury, Benjamin Gould, Victor Ostroverkhov, Thomas Adcock, Steven J. Duclos, Kamel Fezzaa, Christopher Immer, Anthony D. Rollett