Design and development of vacuum system for electron beam powder bed fusion process

• Published in: Vacuum Vol. 231; p. 113779
• Main Authors: Mehta, Avinash Kumar, Gote, Gopal, Solanki, Kalpit, Patil, Yogesh, Mittal, Yash, Ramani, V.N., Karunakaran, K.P.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-01-2025
• Subjects: Analytical design; Electron beam (EB); Finite element analysis (FEA); Powder bed fusion (PBF); Vacuum chamber; Vacuum pumping system; Powder bed fusion (PBF); Analytical design; Finite element analysis (FEA); Electron beam (EB); Vacuum chamber; Vacuum pumping system
• ISSN: 0042-207X
• DOI: 10.1016/j.vacuum.2024.113779

A vacuum system is one of the crucial components of the Electron Beam-Powder Bed Fusion Process (EB-PBF). It ensures the generation of a high-intensity electron beam. This paper presents a vacuum system design for the EB-PBF process. The work chamber and EB gun chamber have been designed and verified using ANSYS workbench for stress, strain, and deformation limits and found satisfactory. The analytical calculations have been performed for all the pumps, considering the various gas loads during the process. After the design, the vacuum system has been fabricated and tested for its stability, ultimate vacuum, and leak rate. The helium leak test results show that all the joints have a leak rate better than 1 × 10−8 mbar l/s. Further, the analytical results of each pump have been compared with experimental results and found almost in line with the theoretical results. The results show that a pressure lower than 1 × 10−5 mbar and 5 × 10−6 mbar can be achieved in the work chamber and EB gun chamber in less than 23 min and 10 min respectively. The chamber was evacuated multiple times and found that the chamber could still hold pressure better than 1 × 10−2 mbar after 48 h.
•The design was verified using ANSYS for its stress, strain, and deformation limits.•The experimental results are almost in line with the analytical calculations.•The system has a leak rate (He) better than 1 × 10−8 mbar l/s at all joint locations.•The chamber can hold a vacuum of 1 × 10−2 mbar even after 48 h of evacuation.•The total pump downtime of the EB-PBF system is less than 23 min.