GB2008460A - Aluminum brazing sheet - Google Patents

Abstract

An aluminum brazing sheet comprises a core 10 of an aluminum alloy, a first layer 20 of an aluminum brazing alloy provided on at least one side of the core to form a composite and a second layer 30 of an aluminum alloy is clad on at least one of the brazing layer and the core. The aluminum alloy of the second layer consists essentially of 0.5 to 1.2 wt.% Mg and 1.2 to 1.8 wt.% Si, the remainder being aluminum, incidental impurities and 0.2 wt.% Cu max., 0.7 wt.% Fe max and 1.5 wt.% Mn max. The second layer has a melting point substantially equivalent to the melting point of the brazing layer. The Al brazing alloy may contain up to 2.5% Mg, 5 to 13 wt.% Si, up to 0.8% wt.% Fe, up to 0.3 wt.% Cu, up to 0.3 wt.% Zn and up to 0.3 wt.% Mn, and the core may contain up to 1.5 wt.% Mn, up to 0.7 wt.% Mg, up to 0.5 wt.% Si, up to 0.7 wt.% Fe, up to 0.25 wt.% Cu, up to 3.0 wt.% Zn and up to 0.25 wt. % Cr. The sheet is produced by roll bonding and then rolling a composite. <IMAGE>