A new method for the flux-free brazing of aluminium alloys in air in a few minutes has been developed which is capable of providing strong bonds with shear strengths close to those of the parent alloys. A key feature of this new method is to use minimal thickness of liquid gallium at the joint interface since this ensures little grain boundary attack and subsequent embrittlement of the aluminium. The approach is to apply a very thin layer of gallium to the faying surfaces which are immediately quenched in liquid nitrogen to stop further diffusion of the liquid gallium into the aluminium. The bonding is carried out by fast heating of the gallium-treated aluminium pieces to a temperature between 400-550degreesC and then holding for a few minutes under a controlled pressure.