AN AL-SI-CU BRAZING FILLER METAL FOIL AND A PREPARATION METHOD AND APPLICATION THEREOF

The invention relates to the technical field of brazing, in particular to an aluminum-silicon-copper brazing filler metal foil and a preparation method and application thereof. The aluminum-silicon-copper brazing filler metal foil comprises a first surface layer, a first middle layer, a core layer, a second middle layer and a second surface layer which are connected in sequence, the first surface layer, the second surface layer and the core layer comprise AlSi alloy layers; the first intermediate layer comprises an Al foil layer; the second intermediate layer comprises a Cu foil layer; in the aluminum-silicon-copper brazing filler metal foil, the mass ratio of Al to Si to Cu is (67-69): (4-6): (25-27); the preparation method comprises the steps that the Al foil and the Cu foil with the surfaces coated with brazing flux paste are subjected to hot dipping in AlSi alloy melt, then stacked and subjected to heating and pressurizing composite treatment. The aluminum-silicon-copper brazing filler metal foil has the advantages of being low in melting temperature, good in flowing property, high in deslagging and degassing capacity and the like; and the problem that aluminum-silicon-copper brazing filler metal is difficult to process into brazing filler metal foil due to high brittleness of the aluminum-silicon-copper brazing filler metal is solved.