METHOD FOR OBTAINING ULTRAHIGH VACUUM IN ELECTRON BEAM WELDING OF NIOBIUM MATERIALS

摘要

A method for obtaining ultrahigh vacuum in the electron beam welding of niobium materials includes: niobium workpieces and sacrificial metal are put into a welding vacuum room which is vacuumized by a vacuum system of a vacuum electron beam-welding machine until ultimate vacuum is reached, an electron beam of the vacuum electron beam-welding machine is utilized for bombarding the sacrificial metal so as to form a weld crater in the electron beam spot area of the surface of the heated sacrificial metal, and the electron beam is started to weld the niobium workpieces in the shortest time within ten minutes. The method can be adopted to provide a higher vacuum environment for the welding of niobium materials, so that the welding of niobium materials can sufficiently avoid the pollution of oxygen, nitrogen and other gaseous impurities, and thereby better niobium material-welding purity can be obtained.