Production of aluminum brazing sheet

A method of producing aluminum brazing sheet comprising the steps of:

• (a) providing a composite assembly comprising
• (i) an ingot of aluminum alloy;
• and
• (ii) at least one side of the ingot provided with a layer of an aluminum brazing alloy consisting essentially of 6.0 to 13.0 wt.% silicon and 0.05 to 0.35 wt.% magnesium, the remainder aluminum and incidental impurities;
• (b) providing on at least one of said ingot and said brazing layer a layer of aluminum for rolling purposes, the layer being substantially free of elemental silicon and consisting essentially of 0.2 wt.% Cu max., 0.4 wt.% Fe max., 0.05 wt.% max. for both Mn and Ti, up to 1.0 wt.% Mg, and up to 0.2 wt.% of at least one of the group consisting of Bi, Pb and Sn, the remainder aluminum and incidental impurities;
• (c) hot bonding the composite assembly and the rolling layers to form a composite by rolling at a temperature in the range of 850.degree. to 950.degree. F. in a reversing mill;
• and
• (d) continuously hot rolling the composite to form brazing sheet.

A method of producing aluminum brazing sheet comprising the steps of:

• (a) providing a composite assembly comprising
• (i) an ingot of aluminum alloy consisting essentially of 0.3 to 1.5 wt.% Mn, 0.15 to 0.3 wt.% Si, 0.2 to 0.45 wt.% Fe, the remainder aluminum;
• and
• (ii) at least one side of the ingot provided with a layer of an aluminum brazing alloy consisting essentially of 6.5 to 12.0 wt.% silicon and 0.05 to 0.25 wt.% magnesium, the remainder aluminum and incidental impurities;
• (b) providing on at least one of said ingot and said brazing layer a layer of aluminum for rolling purposes, consisting essentially of 0.2 wt.% Si max., 0.2 wt.% Cu max., 0.4 wt.% Fe max., 0.05 wt.% max. for both Mn and Ti, up to 1.0 wt.% Mg, the remainder aluminum and incidental impurities;
• (c) hot bonding the composite assembly and rolling layers to form a composite by rolling at a temperature in the range of 850.degree. to 950.degree. F. in a reversing mill;
• and
• (d) continuously hot rolling the composite at a temperature in the range of 500.degree. to 800.degree. F. to form brazing sheet.