| 摘要 |
An object of the present invention is to provide a filler metal for an aluminum brazing sheet for heat exchangers capable of preventing or controlling occurrence of a melting hole during heating for brazing, and a method of manufacturing the same. In an Al-Si alloy filler metal which is clad on the aluminum brazing sheet and melted during heating for brazing, the maximum particle diameter of a coarse Si particle crystallized in the eutectic structure of the filler metal is 20 mum or less. Provided that an average value and a standard deviation in a normal distribution of the particle diameter of the coarse Si particle in the filler metal are respectively mu and sigma, (mu+3sigma) is preferably 10 mum or less. This brazing sheet is obtained by a method of adding a specific amount of Na, Sr, or Sb to the filler metal, a method of limiting the amount of impurities in the filler metal within a specific range, a method of specifying a cooling rate during the casting of the filler metal, or the like. |
