Patent ID: 7226669

Claim:
High strength aluminium-zinc alloy brazing sheet, comprising an Al—Zn core layer, one interlayer on each side of the core layer and a clad layer on each interlayer, said core layer comprising the following composition (in weight percent): Zn 3.0 to 5.0 Mg 1.2 to 2.5 Mn 0.1 to 1.0 Cu <0.2 Si <0.35 Fe <0.5, optionally one or more of: Zr <0.3 Cr <0.3 V <0.3 Ti <0.2 Hf <0.3 Sc <0.5, the balance aluminium and incidental elements and impurities, said clad layer comprising an Al—Si based filler alloy and being applied on at least one side of the core layer, wherein at least one of said interlayers comprises either a sacrificial anode material which is less corrosion resistant than the core layer or a protective material which is more corrosion resistant than the core layer, said sacrificial anode material or protective material comprising Zn, in addition to or instead of Mn, in a range of (in weight %) 1.0 to 2.5.