宇宙半導体レーザ溶接の宇宙適用を目指した光学部品の金属蒸着防止技術

摘要

日本時間2009年7月19日11時23分，国際宇宙ステーrnションISSに長期滞在する君田光一宇宙飛行士は，ロボットrnアームを巧みに操作してスペース?シャトル「エンデバー」rnで打ち上げられた船外実験施設を日本実験棟「きぼう」のrn船内実験室に取り付けた．構想から27年，日本の悲願でrnあった宇宙実験施設「きぼう」が完成した．%In future space developments, the welding in space may be required for the repairs of the ISS and the constructions of lunar base and space structures. The authors have studied the space Gas Hollow Tungsten Arc (GHTA) welding process since 1993. This paper describes the results for space applying the space Diode Laser (DL) welding process which the authors proposed in 2002. It is necessary to prevent the metal deposition on optical devices in order to utilize the space DL welding process in space. The authors studied the preventing technique of metal deposition which covered optical devices with the nozzle and blew the shielding gas out from nozzle outlet. The metal deposition can be reduced by supplying the nozzle with inert gas and blowing the gas out from nozzle outlet. The shielding gas argon perfectly prevents the metal deposition on optical devices when argon pressurizes the nozzle to over 19.9 Pa and spouts out from the nozzle outlet.