The invention relates to an Al-Si-Cu-Zn-Sn-Ni aluminum-based
brazing filler metal and a preparation method thereof. The components of the aluminum-based
brazing filler metal are 7 to 13 percent by weight of Si, 5 to 11 percent by weight of Cu, 4 to 11 percent by weight of Zn, 1 to 6 percent by weight of Sn, 1 to 3 percent by weight of Ni, 0.02 to 0.3 percent by weight of Ce, 0.01 to 0.1 percent by weight of Sr, 0.01 to 0.2 percent by weight of Zr and the balance of Al. The process flow for preparing the aluminum-based
brazing filler metal is that: pure aluminum is added into a
graphite crucible and covered by flux for aluminum under the condition of 800 DEG C to 900 DEG C, and
slag is removed after melting; the aluminum-based intermediate
alloy of high-
melting point elements and flux for aluminum are added at the same time, and melting, stirring and
slag removal are carried out; the aluminum-based intermediate
alloy of low-
melting point elements is added under the protection of
nitrogen, and melting and stirring are carried out; the mixture of
argon and
hexachloroethane is added to carry out refining, and standing and
slag removal are carried out; the intermediate
alloy of trace elements is added, and melting and stirring are carried out; secondary refining and slag removal are carried out; and under the protection of
nitrogen,
casting formation is carried out. The Al-Si-Cu-Zn-Sn-Ni aluminum-based brazing filler
metal has the advantages of
low melting point, high strength, high
toughness, high
corrosion-resistant property and good
wetting property and
spreadability.