Fluxless soldering of aluminium using crimped joints - where crimping deformation breaks up oxide film on molten solder

摘要

The mating surfaces are coated with a film of solder, and then a heated froming device is employed to apply press. on the segments melting the solder and reducing its thickness to a min., together with deformation of the segments and their relative movement wrt the solder. The oxide film on the solder is ruptured and does not form a continuous layer; a good soldered joint is thud obtd. The wall segments are pref. Al, and the heat and pressure is pref. applied for 2-6 seconds esp. using a press. of >=35 kg/cm2. Used for soldered joints employed in heat exchangers.