Patent ID: 7648776

Claim:
A multi-layer brazing sheet comprising: a core of a 3xxx alloy, an inner braze cladding of a 4xxx alloy, and between core and inner braze cladding an interliner comprising an interliner alloy selected from the group consisting of a 3xxx, 1xxx and 7xxx alloy, wherein the interliner has a lower level of Mn than the core, and wherein the 3xxx alloy of the core comprises: 0.55-1.0 wt % Cu 0.65-1.8 wt % Mn <0.3 wt % Mg <0.4 wt % Zn <1.0 wt % Si <0.7 wt % Fe and optionally one or more of <0.3 wt % Cr <0.02 wt % Ti, and one or more of V, Zr, In, Sc, Sn, each in a range of up to 0.5%, balance aluminium and unavoidable impurities, and wherein the interliner alloy comprises 0.1-5.0 wt % Zn, wherein if the interliner alloy is 3xxx then the 3xxx interliner alloy further comprises 0.5 to 1.5 wt % Mn.