| 摘要 |
PROBLEM TO BE SOLVED: To provide a brazing filler metal having sufficient corrosion resistance even under an environment in which, e.g. a deteriorated alkaline refrigerant circulates at high speed and erosion occurs easily and to provide a composite material (brazing sheet) using the same brazing filler metal. SOLUTION: The anticorrosive aluminum alloy brazing filler metal for a heat exchanger has a composition containing, by weight, >5 to 15% Si, 0.4 to 2% Fe, 0.2 to 2% Ni and the balance Al with inevitable impurities. The highly corrosion resistant aluminum alloy composite material for a heat exchanger is obtained by cladding the same brazing filler metal on one side of an aluminum alloy core material and cladding an Al-Zn based alloy sacrificial material on the other side. The brazing filler metal has excellent erosion resistance since suitable amount of Fe and Ni are incorporated into an Al-Si alloy and a hydroxide film on the surface thereof is made dense and firm, and even when used for the refrigerant passage of a heat exchanger as a brazing sheet, the leakage of liquid occurs hardly in the brazed part.
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