Abstract: An aluminum alloy thermal exchanger has an aluminum alloy metal surface without any harmful chromium ions and having good corrosion resistance and good hydrophilicity. The thermal exchanger includes an aluminum alloy metal having a surface provided with a first protective layer of chemical conversion coating produced by using a first treatment liquid, the first treatment liquid including a water soluble vanadium compound and a fluoro-zirconium complex compound. The first protective layer has a second protective layer of hydrophilic film thereon.

Abstract: A heat exchanger includes at least one elongate header of metal, a plurality of refrigerant flow tubes each having one open end exposed to the interior of the header and a plurality of heat radiation fins extending along the tubes. A connector of metal is brazed to the header to provide a fluid communication between the interior of the header and an external pipe member through an opening formed in a wall of the header. The connector comprises a mating surface which mates the wall of the header; a connecting surface positioned at an opposite side of the mating surface; a pair of side surfaces each being positioned between the mating and connecting surfaces; a through bore which extends between the mating and connecting surfaces; and a groove formed in each of the side surfaces along an axis of the elongate header. The groove is positioned close to the mating surface to leave or define therebetween a thin mounting portion of the connector.