Simulating the Electron Optics of an Electron Beam Manufacturing 3D Printer

Abstract

Additive Manufacturing (AM) is a growing industry that has the potential to completely revolutionize global manufacturing. Electron Beam Manufacturing (EBM) is a 3D-printing method developed by GE Additive that utilizes an electron beam, controlled by a magnetic lens system, to melt metal powder. GE is currently looking into opportunities for simulating the Electron Optics, with the ambition to further develop their EBM technology. In this project a model of the lens system has been built and evaluated in COMSOL Multiphysics®. Using the Finite Element Method (FEM) and Time Step Particle Tracing it was possible to simulate the electron trajectories in 25 min. The computational time was substantially reduced by approximating certain calculations and replacing COMSOL’s default Generalized Alpha Time Stepping algorithm with a simpler algorithm in certain regions. The accompanied decrease in accuracy was negligible compared to the error in the model itself, proving that there is a lot of potential for improvement. The thesis concludes that COMSOL is a useful FEM software for simulating the electron optics of an Arcam EBM lens system. The model created in this thesis does however require further development, especially regarding mesh convergence, before the software can be implemented as a simulation tool at GE Additive.