ALUMINIUM ARTICLES FLUXLESS SOLDERING METHOD Russian patent published in 1999 - IPC

FIELD: mechanical engineering; production of plate-fin heat exchangers. SUBSTANCE: article is assembled with silumin-based solder arranged in zone of soldering and is placed in furnace chamber with solid nondispersible getter. Chamber is subjected to repeated evacuation with filling in, after each evacuation, with inert gas, dew point not higher than -90 C with oxygen content not exceeding 5•10^-5 vol.%. Then article and getter are heated to soldering temperature by inert gas. Then degassing is carried out after heating to 300-320 C vacuum (1-9)•10^-2 Pa during 1-10 h, and after heating to 500-520 C in vacuum (1-9)•10^-1 Pa during 11-3 h. Then article is cooled to 400-450 C in static atmosphere of inert gas. Circulation and temperature rise of inert gas in process of soldering is provided by aerodynamic heaters built into furnace chamber. EFFECT: enhanced quality of soldered joints.