FLUX COMPOSITION FOR BRAZING, AND POWDER BRAZING COMPOSITION, AND ALUMINUM ALLOY MEMBER AND HEAT EXCHANGER

摘要

To provide a flux composition having excellent application stability, coating dryability and coating adhesion, and a powder brazing composition, and an aluminum alloy member and a heat exchanger including the same.SOLUTION: A flux composition has fluoride flux, resin and solvent, the solvent being water or water-soluble organic solvent. The ratio of an amount of evaporation of solvent a relative to an amount of evaporation of butyl acetate is defined as a relative amount of evaporation of the solvent a Q. Regarding the relative amount of evaporation Qobtained by the following formula, with Q60 of solvent 1, 60≥Q10 of solvent 2, Q≤10 of solvent 3, solvent 1: solvent 2: solvent 3=0-20%: 30-70%: 10-60% is satisfied. Q=(P×√M)/(P×√M)×100 (Q: relative amount of evaporation of solvent a, P: saturation vapor pressure of solvent a (20°C), M: molecular mass of solvent a, P: saturation vapor pressure of butyl acetate (20°C), M: molecular mass of butyl acetate).SELECTED DRAWING: Figure 1