| 摘要 |
PROBLEM TO BE SOLVED: To obtain an excellent alkaline corrosion resistance and to prevent the occurrence of through holes due to a pitting corrosion by incorporating specific amounts of Fe, Ni, and In into an Al alloy as a sacrificial anode material of an Al alloy clad material. SOLUTION: One side of a core material composed of Al alloy is clad with an Al-Si brazing filler metal and the other side is clad with a sacrificial anode material, by which an Al alloy clad material for heat exchanger is formed. This sacrificial anode material has a composition consisting of, by weight, 0.5-3.0% Fe, 0.1-3.0% Ni, 0.01-0.2% In, and the balance Al with inevitable impurities and satisfying Fe+Ni<=3.0%. Further, if necessary, one or >=2 kinds among 0.1-2.5% Mg, 0.5-4.0% Zn, 0.01-0.2% Sn, and 0.01-0.2% Ga are incorporated. Fe and Ni in the composition form Al-Fe-Ni compounds and these are finely dispersed in a matrix. It makes the electric potential of the sacrificial anode material base and makes the sacrificial anode material produce a sacrificial anode effect on the core material with certainty. |
