Electron beam melting additive manufacturing process efficiency study of stainless steel

Electron Beam Additive Manufacturing (EBAM) is a powder bed-based Additive Manufacturing (AM) technology, considered to be an innovative industrial production technology. EBM employs an electron beam in a vacuum environment to selectively melt a metallic powder bed directed by a computer aided design (CAD) model. Although it is generally assumed that the efficiency of the process is 90%, to date, no studies have verified this—especially when the cathode is set in a grid cup that works as a throttle for the electron beam; hence, the process’s efficiency remains unknown. Detailed Monte Carlo simulations and experiments were conducted in this study using EGS5 and an Arcam Q20 + system. Experiments utilized a custom-built Faraday cup to ultimately calculate what percentages of current pass through the grid cup into the build chamber. Following experiments discovered how variations in velocity and focus offset have no impact on EB efficiency. Also, the experiment validates the MC simulations and demonstrates how EB efficiency increased when surface morphology of the substrate was altered.