Aluminum alloy brazing sheet for heat exchangers and aluminum alloy brazed article for heat exchangers

Abstract

Disclosed is an aluminum alloy brazing sheet ( 1 ) for heat exchangers, the brazing sheet provided with a core material ( 2 ) and a filler material ( 3 ) that comprises an Al—Si—Zn alloy and is formed on at least one side of the core material ( 2 ). The core material ( 2 ) has a pitting potential of −650 mV or more (vs. Ag/AgCl). The filler material ( 3 ) has a zinc concentration of from 1 to 10 percent by mass; a liquid fraction X, at the brazing temperature, satisfying the relation 0.3≦X≦0.88; and a clad ratio d (%) satisfying the relation 15<d≦30. The filler material has a product (X×d) of the liquid fraction X and the clad ratio d (%) satisfying the relation 6≦X×d)≦23.

1 - 6 . (canceled) 
     
     
         7 : An article comprising a brazed aluminum alloy brazing sheet, said aluminum alloy brazing sheet comprising:
 a core material having a pitting potential of −650 mV (vs. Ag/AgCl) or higher; and   a filler material on at least one side of the core material and comprising an Al—Si—Zn alloy, wherein the filler material comprises a Zn content of from 1 to 10 percent by mass, has a liquid fraction of X at a brazing temperature, and is present in a clad ratio of d (%), wherein X and d satisfy the conditions: 0.3<X<0.88 and 15<d<30, and wherein the product (XHd) of the liquid fraction X and the clad ratio d (%) satisfies the condition: 6<(XHd)<23,   wherein the filler material remains as a residual layer on the core material in the brazed aluminum alloy brazing sheet, the residual layer has a thickness of 5% or more of a gauge of the aluminum alloy brazing sheet, and the residual layer comprises an alpha phase comprising Zn in a content of 1 percent by mass or more and has an area percentage of 75% or more.   
     
     
         8 : The article of  claim 7 , wherein the filler material of the aluminum alloy brazing sheet comprises a Zn content of Y by mass percent and has a thickness of D (μm), and
 wherein the product (YHD) of Y and D satisfies the condition: 120<(YHD)<480. 
 
     
     
         9 : The article of  claim 7 , wherein the filler material of the aluminum alloy brazing sheet comprises a Mn content of less than 0.05 percent by mass. 
     
     
         10 : The article of  claim 7 , wherein the filler material of the aluminum alloy brazing sheet comprises a Cu content of 0.05 percent by mass or more and 0.7 percent by mass or less. 
     
     
         11 : The article of  claim 7 , wherein the core material of the aluminum alloy brazing sheet comprises a Cu content of 1.5 percent by mass or less, a Si content of 1.5 percent by mass or less, a Mn content of 1.8 percent by mass or less, a Ti content of 0.35 percent by mass or less, and a Mg content of 0.5 percent by mass or less, with the remainder comprising Al and inevitable impurities. 
     
     
         12 : The article of  claim 7 , which is a heat exchanger. 
     
     
         13 : The article of  claim 7 , which is a heat exchanger for an automobile.