Patent ID: 7438121

Claim:
A method for manufacturing an aluminum heat exchanger, the method comprising the steps of: providing a heat exchanger tube by forming a Zn thermally sprayed layer on an outer surface of an aluminum flat tube core so as to provide a Zn adhesion amount of 2 to 6 g/m 2 covering 10 to 90% of a total area of the outer surface of the aluminum flat tube; assembling a heat exchanger core by alternately arranging the heat exchanger tube and an aluminum fin and brazing the heat exchanger tube and the fin with end portions of the heat exchanger tube connected in fluid communication to respective aluminum headers; and forming a corrosion resistance coat on a surface of the heat exchanger core by subjecting the surface of the heat exchanger core to chemical conversion treatment using at least one chemical conversion treatment agent selected from the group consisting of phosphoric acid chromate, chromic acid chromate, phosphoric acid zirconium series, phosphoric acid titanium series, fluoridation zirconium series, and fluoridation titanium series.