PRODUCTION OF HOLLOW EXTRUDED PROFILE MADE OF ALUMINUM FOR VACUUM

摘要

PURPOSE:To obtain an aluminum hollow extruded profile for vacuum which satisfies mechanical strength and has small electric resistance by using a composite material composed of an aluminum core material and aluminum alloy skin material having specific purity for a billet for extrusion and forming an inside layer and outside layer corresponding to the core material and skin material. CONSTITUTION:The composite billet 14 is formed of the high-purity aluminum core material 18 having 99.9% purity and the Al-Mg-Si alloy skin material 17. A gaseous mixture composed of oxygen and argon from a vessel 11 is ejected from an ejection port 8 via a conduit 12 and is supplied into the hollow part of the profile 13 simultaneously with extrusion. The aperture at the top end of the slightly extruded profile 13 is press welded to form a sealed end 16. The profile 13 is formed with the inside layer 20 and outside layer 19 corresponding respectively to the core material 18 and the skin material 17 and is extruded to a prescribed length; thereafter, the profile is cut and at the same time, the cut end is sealed to form the other sealed end 21. The hollow extruded profile 13 is adequate for a beam chamber for a particle accelerator used in a high vacuum state and obviates the instability of a high-energy beam even if said beam is run therein.