Sumitomo Light Metal Industries, Ltd.

Denso Corporation

Harima Chemicals, Incorporated

Takashi Hatori

Taketoshi Toyama

Yuji Hisatomi

Yasunaga Itoh

Yoshiharu Hasegawa

Yoshifusa Shoji

Ryoichi Sanada

Koji Hirao

Ichiro Taninaka

Yuji c/o Sumitomo Light Metal Industries Ltd Hisatomi

An aqueous aluminum brazing composition containing an organic binder and a zinc-based flux which prevents the precipitation of the zinc-based flux having a large specific gravity while securing an excellent brazeability. The thixotropic index of the brazing composition is adjusted to 1.01-1.20 by adding a (meth)acrylic acid/(meth)acrylate copolymer emulsion to the brazing composition as a precipitation inhibitor in an amount of 0.03-1.50 wt % of 100 wt % of the brazing composition. Since the (meth)acrylic acid/(meth)acrylate copolymer emulsion is used as the precipitation inhibitor in a specific amount instead of other types of compounds used for a powder-containing paint, such as ultrafine particle silica, poly(meth)acrylate, or polyvinyl alcohol, the precipitation of the zinc-based flux can be prevented without impairing the brazeability.

Aqueous aluminum brazing composition, aluminum material coated with the brazing composition, brazing method using the aluminum material, and automotive heat exchanger manufactured by using the brazing method

The present invention provides an aluminum alloy fin material for heat exchangers which has a thickness of 80 &#x3bc;m (0.08 mm) or less and excels in joinability to a tube material and in intergranular corrosion resistance. The aluminum alloy fin material is an aluminum alloy bare fin material or a brazing fin material which has a thickness of 80 &#x3bc;m or less and is incorporated into a heat exchanger made of an aluminum alloy manufactured by brazing through an Al&#x2014;Si alloy filler metal. The structure of the core material before brazing is a fiber structure, and the crystal grain diameter of the structure after brazing is 50&#x2013;250 &#x3bc;m. The Si concentration in the Si dissolution area on the surface of the fin material and at the center of the thickness of the fin material after brazing is preferably 0.8% or more and 0.7% or less, respectively.

Aluminum alloy fin material for heat exchangers and heat exchanger including the fin material

Growing community of inventors

Kariya, Japan

Takashi Hatori