Simulation and Characterisation of Morphology of Meltpool in Electron Beam Powder Bed Fusion of Copper

Additive Manufacturing (AM) is an emerging manufacturing process that has been widely used in different high-value industries such as aerospace, defence, automotive and medical. Among all different AM processes, powder bed fusion, directed energy deposition and binder jetting are common to process the metal components. In this research, the electron beam powder bed (EB-PBF) fusion process of pure copper for single tracks component is investigated. The effect of input parameters comprising of beam power, beam speed, and layer thickness on manufacturability including dimensional accuracy and surface quality are discussed. The next phase of this project is to examine the effect of EB-PBF process parameters on the thermal history, morphology of meltpool in the context of the fundamental phenomena that drive the EB-PBF response. To achieve this, a numerical multiphysics simulation of the EB-PBF process will be conducted using computational software such as Flow3D. The numerical simulation is based on powder interaction with the electron beam and the fundamental rheological phenomena during the process. This can then be related to the effect of process parameters on both temperature (both qualitatively and quantitatively) and meltpool features and morphology (transient and steady-state width, depth) as well as fusion mode (for example transition from conduction mode to keyhole mode). Numerical simulation has the potential to provide comprehensive information on both morphology and temperature as well as transient and steady-state phenomena, it is associated with a high computational cost. As an alternate prediction capability, an analytical model was developed to estimate meltpool temperature. Although this analytic method cannot provide insight onto meltpool morphology, or transient behavior, it has the potential to provide computationally rapid insights into the effect of process parameters and material properties on steady state average melt-pool temperature. The final stage of this study involves experimentally assessing the impact of EB-PBF copper process parameters of beam power and scanning velocity on the morphology of the deposited melt-track temperature. This data can be used to provide corroborating insights into the predictions of the numerical simulation and analytical model of the melt pool. By providing previously unavailable predictive models and experimental data on associated meltpool phenomena, this research contributes valuable insights for the optimization and understanding of the manufacturing process into EB-PBF of pure copper, with potential applications in various industries.