Aluminum heat exchanger

Abstract

An aluminum-made heat exchanger including a flat tube is formed by, using an aluminum strip-shaped material coated with a brazing metal on the outer surface of a core metal and coated with a sacrificial anode material at the inner surface side thereof, bending the strip-shaped material in the width direction thereof, wherein many flat tubes are diposed parallel with each other and joined using a flux in a furnace. In order to provide the aluminum-made heat exchanger capable of being satisfactorily brazed and a high strength after brazing, the brazing metal is of an Al—Si alloy, core metal is an Al—Si alloy including Si of 0.4 to 1.2% by weight, and the sacrificial anode material is of an Al—Mg—Zn alloy including Mg of 0.3 to 0.75% by weight.

1 . An aluminum-made heat exchanger, comprising: 
 a flat tube formed by, using an aluminum strip-shaped material of which core metal is coated with a brazing metal on the outer surface thereof and is coated with a sacrificial anode material on the inner surface thereof, bending the strip-shaped material in the width direction, many flat tubes are disposed parallel to each other to form a core of the heat exchanger, and each of these parts are fixed integrally by means of brazing,    wherein the brazing metal is of an Al—Si alloy, the core metal is of an Al—Si alloy including Si of 0.4 to 1.2% by weight, the sacrificial anode material is of an Al—Mg‘ 3 Zn alloy including Mg of 0.3 to 0.75% by weight, the aluminum-made heat exchanger is structured by being subjected to a brazing in a furnace using a flux for brazing to join the parts being interposed by the brazing metal.    
   
   
       2 . The aluminum-made heat exchanger according to  claim 1 , wherein the brazing metal of an aluminum alloy including Si of 7.5% to 12% by weight, the core metal is equivalent to A3003 aluminum material added with Si of 0.4 to 1.2% by weight, the sacrificial anode material is equivalent to A7072 added with Mg of 0.3 to 0.75% by weight.