| abstract |
Method of fluxless soldering of aluminium members, at least one of which being provided with an adherent diffusion bonded coating of solidified solder comprising preheating of the members to a temperature above the melting point of the solder, forming in situ a solder pool, bringing the members together at this elevated temperature, applying simultaneously mechanical agitation direction to at least one of the members is disclosed. A heat exchanger (1) is provided having a core of spaced solder coated hair pin tubes (7) and interconnecting fins (8) extending from a liquid tank, where the hair pin tubes (7) comprising two parallel leg portions (71) having substantially an oval cross-section integrally joined by a U-shaped bend (74) of circular cross-section are soldered into the liquid tank and the interconnecting fins (8) |