Effect of Laser-Matter Interaction on Molten Pool Flow and Keyhole Dynamics

In laser-based welding and additive manufacturing, the interaction of the laser with the metal leads to the formation of a cavity known as a keyhole, which can fluctuate unstably during the process. This work significantly advances our understanding of laser-induced keyholes and their dynamics, by combining state-of-the-art dynamic x-ray radiography with multiphase, multiphysics modeling. Numerical simulations of keyhole morphologies are validated by experiment, then leveraged to predict transient nonuniform distributions of laser absorption, temperature, and flow velocity in the complex multiphase process.