Computer-based design of optimal laser intensity profiles for L-PBF/M: verification and validation
Please login to view abstract download link
We present a framework for laser beam shaping in L-PBF/M that uses an advection-diffusion model to compute a laser intensity profile corresponding to a desired temperature field (i.e. melt pool shape)[1]. To solve this inverse problem, we minimize the functional given by the squared difference between the predicted and the desired temperature field integrated over the domain using the adjoint-based optimization method. The melt pool dimensions produced by the computed laser intensity profile are validated using photomicrographs of experiments. However, other quantities such as temperature profiles, temperature gradients, or dynamic effects cannot be validated experimentally. To this end, the computational results are compared to high-fidelity melt pool models (using Smoothed Particle Hydrodynamics). Additionally, we will discuss how the process windows within which the presented models are valid and present new types of laser intensity profiles designed to achieve a wide, shallow, yet stable melt pool in conduction mode. [1]. V. Holla, P. Kopp, J. Grünewald, K. Wudy, S. Kollmannsberger, "Laser Beam Shape Optimization in Powder Bed Fusion of Metals.", available at: https://dx.doi.org/10.2139/ssrn.4265496.