高真空環境下における宇宙半導体レーザ溶接実験

摘要

The authors have been developing the space Gas Hollow Tungsten Arc (GHTA) welding process for space application since 1993. We have also been developing the space Diode Laser (DL) welding which its welding principle differs from the space GHTA welding. The metal vapor deposition on optical devices caused in the DL welding experiments in a vacuum can be prevented by using the shielding gas. We performed the butt welding experiments with SUS304 stainless steel and A2014-T6 aluminum alloy at the International Space Station (ISS) orbital pressure. The mechanical properties of butt welding joints, and the effect of root gap and filler metal addition on weld metal shape were clarified.%宇宙開発に必要不可欠な溶接技術をより確実に実用化するために，宇宙GHTA溶接とは溶接原理の全く異なる宇宙DL溶接法いを提案した.真空環境中のレーザ溶接では，金属蒸着による光学部品の損傷の問題があったが，ノズルを取りつけ，Arガスをシールドガスとして流すことにより解決した.そこで本研究では，宇宙DL溶接法で突合せ溶接継手を製作し，ルートギャップ，溶加ワイヤ添加の有無が溶接金属形状に及ぼす影響や継手強度などの機械的性質を明らかにした.