Aluminum alloy clad material

Abstract

The aluminum alloy clad material includes a core material and sacrificial materials disposed on both surfaces of the core material, the composition of the core material contains, by mass %, Mn: 0.7% to 1.8%, Si: 0.3% to 1.3%, Fe: 0.05% to 0.7% and Zn: 0.5% to 3.0% with a remainder consisting of Al and inevitable impurities, the composition of the sacrificial material contains, by mass %, Mn: 0.005% to 0.7%, Fe: 0.05% to 0.3% and Zn: 1.0% to 4.0% with a remainder consisting of Al and inevitable impurities, an amount of Zn in the sacrificial material is larger than an amount of Zn in the core material by 0.2% or more, and the potential of the core material after a brazing heat treatment is within a range of −700 to −870 mV.

1 . An aluminum alloy clad material, comprising:
 a core material; and   sacrificial materials disposed on both surfaces of the core material; wherein;   a composition of the core material comprises, by mass %, Mn: 0.7% to 1.8%, Si: 0.3% to 1.3%, Fe: 0.05% to 0.7% and Zn: 0.5% to 3.0% with an Al balance containing inevitable impurities;   a composition of the sacrificial materials comprises, by mass %, Mn: 0.005% to 0.7%, Fe: 0.05% to 0.3% and Zn: 1.0% to 4.0% with an Al balance containing inevitable impurities;   an amount of Zn in the sacrificial materials is larger than an amount of Zn in the core material by 0.2% or more by mass %; and   a potential of the core material after a brazing heat treatment is within a range of −700 to −870 mV.   
     
     
         2 . The aluminum alloy clad material according to  claim 1 , wherein a potential difference between each of the sacrificial materials and the core material (a core material potential—a sacrificial material potential) is 20 to 100 mV after the brazing heat treatment. 
     
     
         3 . The aluminum alloy clad material according to  claim 1 , wherein an amount of a Mn solid solution in the core material after the brazing heat treatment is larger than an amount of a Mn solid solution in each of the sacrificial materials by 0.2% or more by mass %. 
     
     
         4 . The aluminum alloy clad material according to  claim 2 , wherein an amount of a Mn solid solution in the core material after the brazing heat treatment is larger than an amount of a Mn solid solution in each of the sacrificial materials by 0.2% or more by mass %.