Additive manufacturing of an oxide ceramic by laser beam melting-Comparison between finite element simulation and experimental results

摘要

Recent progress in the application of Laser Beam Melting (LBM) of oxide ceramics has shown promising results. However, a deeper understanding of the process is required to master and control the track development. In this approach numerical modeling could allow higher quality, of additive manufacturing for such materials, to be achieved. The validation of an earlier developed finite element model for LBM of ceramic materials has been established through a comparison with experimental results. The model solves heat and mass transfers whilst accounting for fluid flow due to surface tension and Marangoni convection, as well as tracking the material/gas boundary. The volumetric heat source parameters used in the simulations have been calibrated with an analytical model combined with original in-situ reflectance measurements. Numerical results show good agreement with measurements of melt pool dimensions and shapes. They also provide a coherent description of the evolution of the track morphology when varying the heat source parameters. Track irregularities have also been revealed by simulations at high scanning speed and the balling effect highlighted and explained through similar simulations.