| 摘要 |
PROBLEM TO BE SOLVED: To provide a brazing material for an aluminum brazing sheet for a heat exchanger and a manufacturing method therefor, not generating a molten hole in brazing-heating, or capable of suppressing the generation of the molten hole. SOLUTION: In an Al-Si-based metal brazing material which is cladded on an aluminum brazing sheet and melts in brazing-heating, the maximum particle size of a coarse Si particle crystallizing in the eutectic structure of the brazing material is made to be 20μm or less. When a mean value in a normal distribution of a particle size of the coarse Si particle in the brazing material is denoted byμ, standard deviation is denoted byσ, the value of (μ+3σ) is preferably made to be 10μm or less. This brazing sheet can be obtained by a method wherein Na, Sr, Sb are added in the brazing material by a specified amount, a method wherein the amount of impurities in the brazing material is limited in a specified range, a method wherein the cooling speed in casting of the brazing material is specified, etc. |
