Presentation Information
[1F02]Hybrid Laser Welding of 0.2% Be-Cu Alloy for Ultra-High Vacuum Systems
*Takao Nakamura1, Masanao Sasaki2, Kazunai Okahashi2, Shinsuke Kishikawa2, Masahide Kuroiwa2 (1. Mie University, 2. Tokyo Electronics Co., Ltd.)
0.2wt% Be-Cu (BeCu) offers significantly better thermal conductivity, lower thermal radiation, and reduced outgassing compared to stainless steel (SUS), making it ideal for vacuum components. However, its use has been limited due to high material and processing costs, particularly the difficulty in welding. This study explores BeCu welding using a Blue+IR hybrid laser. Key trials include butt welding of BeCu plates and fabrication of a one-side rotating nipple (ICF70), unachievable via machining. Welding with a fixed laser and rotating BeCu achieved leak rates below 10-11 Pa·m3/sec. Post-processing and heat treatment preserved the seal integrity. Additionally, SUS/BeCu dissimilar welds showed tensile strength exceeding that of Cu, demonstrating the method’s feasibility. These advances enable new BeCu-based vacuum components with high reliability.