Abstract: An improved aluminum base alloy which provides corrosion protection in fin stock applications includes 0.6-3.0% silicon; 0.2-1.0% by weight iron; up to 0.2% by weight copper; 0.8-2.0% by weight manganese; up to 0.2% by weight magnesium; from about 0.5% by weight zinc to 2.5% by weight zinc; up to 0.2% by weight other constituents; and the balance aluminum. The alloy is especially useful as a sacrificial alloy having improved mechanical strength.

Abstract: A composite brazing material is described, composed of a layer (usually an ingot) of high manganese content aluminum alloy (3000 series alloy; the "core") and a layer of high silicon content aluminum alloy (4000 series alloy; the "cladding") with a layer of aluminum alloy having the following composition:______________________________________ silicon 6.8-8.2 wgt. % iron up to 0.8 wgt. % copper up to 0.25 wgt. % manganese up to 0.10 wgt. % zinc up to 0.20 wgt. % other elements up to 0.15 wgt. % aluminum balance ______________________________________disposed between the cladding and core layers and in contact with both. Subsequent hot rolling of the multi-layer composite produces a good bond between the core and the cladding through the intermediate layer. The resulting brazing material has the external properties of a simple two-layer composite of core and cladding without the intermediate layer.