Method of making fluxless soldered joints and heat exchangers provided by such method.

摘要

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)