Aluminum alloy brazing sheet having high strength, high corrosion resistance and high material elongation, and method of manufacturing heat exchanger

An aluminum alloy brazing sheet configured to be subjected to brazing, the brazing sheet comprising an aluminum alloy clad material comprising a core material having a first surface and a second surface, the first surface of the core material being clad with a sacrificial material, and the second surface of the core material being clad with a brazing filler metal which is Al—Si-based or Al—Si—Zn-based, wherein:

• the core material has a composition containing 1.3 to 2.0% Mn, 0.6 to 1.3% Si, 0.2 to 0.5% Fe and 0.85 to 1.3% Cu, by mass, with the balance comprising Al and unavoidable impurities;
• the sacrificial material has a composition containing more than 4.0% and up to and including 8.0% Zn, 0.7 to 2.0% Mn, 0.3 to 1.0% Si, 0.3 to 1.0% Fe and 0.05 to 0.3% Ti, by mass, with the balance comprising Al and unavoidable impurities;
• the core material has a lamellar crystal grain structure;
• the brazing sheet has an elongation of at least 4%;
• and
• the brazing sheet has a tensile strength of at least 170 MPa after a heat treatment corresponding to brazing, the heat treatment comprising heating the brazing sheet of 600° C. in about 7 minutes, maintaining the brazing sheet at 600° C. for 3 minutes, and then cooling the brazing sheet at a cooling rate of 100° C./min.