In-situ electron beam characterization for electron beam powder bed fusion

• Published in: Additive manufacturing 2024-09, Vol.96, p.104567, Article 104567
• Main Authors: Markl, Matthias, Azadi Tinat, Mohammad Reza, Berger, Timo, Westrich, Yannic, Renner, Jakob, Körner, Carolin
• Format: Article
• Language: English
• Subjects: Additive manufacturing; Beam diameter; Beam profile; Electron beam powder bed fusion; Electron optical imaging; Process monitoring; Ray tracing
• ISSN: 2214-8604
• DOI: 10.1016/j.addma.2024.104567

Electron beam powder bed fusion is an advanced additive manufacturing technology that utilizes an electron beam to fabricate complex metallic components layer by layer. It is well known, that the beam profile is one of the most important key ingredients for successful processing. Surprisingly, the beam profile during the process is almost unknown until today. The state of the art in beam characterization comprises pre-processes applying different beam measurement devices which ensure a beam profile evaluation at one or a small number of fixed locations on the build area. To the knowledge of the author, there exist no technique to measure the beam profile in-situ during manufacturing at arbitrary locations on the build area. This study presents a groundbreaking method for an in-situ measurement technique of the beam profile for electron beam powder bed fusion. The method exploits electron optical images of a sintered powder bed after preheating. After converting the image into the frequency space by a Fourier transformation, the beam profile is reconstructed. In this work we demonstrate the feasibility on a focused electron beam with an elliptical Gaussian intensity distribution. This real-time assessment capability, completed within seconds, marks a significant advancement in the field of electron beam powder bed fusion, promising to improve manufacturing outcomes through enhanced process optimization and beam profile monitoring. [Display omitted] •Groundbreaking method to measure the beam profile in electron beam powder bed fusion•Method applies electron optical images of the powder bed•Only available in-situ method without any additional device•Beam profile measurement at different locations on the build area•Typical beam powers for the manufacturing process can be used