MULTI-PHYSICS MODELING OF LASER INTERACTION WITH SURFACE IN POWDER BED MELTING PROCESS

Powder bed metal additive manufacturing process using laser or electron beam heat source is gaining increasing popularity due to its ability to create complex shaped metallic components. The process is a complex multi-physics process where multiple phases of material exist and laser interacts through multiple physical mechanisms with the surface of these materials and phases. The power absorption depends on optical and thermos-physical properties of the surface and laser type and wavelength. Most of the work conducted in the past have modeled the laser using a moving heat source. These studies typically assume a certain absorption without actual calculation of this power absorption. This study focuses on modeling the process in a more comprehensive manner including the laser physics and evaluating how this physics affects the temperature distribution and build outcome. The results are compared with the conventional techniques where simple Gaussian distribution was used for the power source. The temperature profile obtained with this study was lower than the Gaussian beam.