| 摘要 |
PURPOSE: To improve the strength and corrosion resistance of an aluminum alloy composite material and to attain its correspondence to the thinning of a heat exchanger tube by specifying the compsn. of the core material in a composite material and using aluminum compositely incorporated with Zn and Ca as a sacrificial material. CONSTITUTION: As for this composite material, the core material has a compsn. contg., by weight, 0.4 to 1.3% Si, 0.1 to 0.7% Fe, 0.1 to 1.0% Cu and 0.5 to 1.5% Mn, moreover contg. one or >= two kinds among 0.2% Mg, 0.05 to 0.3% Ti, 0.05 to 0.3% Cr and 0.05 to 0.3% Zr, and the balance Al with inevitable impurities. One side of this core material is clad with an Al-Si brazing filler metal, and the other side of the core material is clad with a sacrificial material contg. >2.0 to 6.0% Zn, 0.01 to 1.0% Ca, and the balance Al with inevitable impurities. Zn in the sacrificial material gives a sacrificial anode effect, and Ca prevents the evaporation of Zn at the time of vacuum brazing. |
