A macroscale heat transfer analysis of the build chamber in a commercial electron beam powder bed fusion (EB-PBF) additive manufacturing system during component fabrication

Abstract

In this research, a 3D numerical thermal cavity radiation model was developed to predict the evolution of the macroscale thermal field within the build chamber of a commercial EB-PBF system. The model was applied to predict the evolution of the thermal field in a component during fabrication. A combination of quantitative and qualitative data extracted from an ARCAM Q20Plus machine was used to validate the model. The results indicate that the portion of heat transferred to the inner Heat Shield via cavity radiation was a strong function of the Start Plate’s temperature, reaching 88% of the total heat input at a peak temperature of ∼725 °C. Once validated, the thermal model was used to analyse heat transport within the build chamber during the fabrication of a component. The outcomes revealed variability in temperature within the hexagonal base, up to 118 °C, and the powder bed below the platform of 107 °C. Moreover, substantial temperature variations exceeding 200 °C were identified within the component, specifically between the hexagonal base and the platform.