ALUMINUM ALLOY BRAZING SHEET AND METHOD FOR MANUFACTURING THE SAME, AND METHOD FOR BRAZING ALUMINUM-MADE HEAT EXCHANGER

摘要

PROBLEM TO BE SOLVED: To provide an aluminum alloy brazing sheet which includes an aluminum alloy containing Mg as a core material and enables brazing in an inert gas atmosphere without using a flux.SOLUTION: An aluminum alloy brazing sheet is formed by cladding one or both surfaces of an aluminum alloy core material with an Al-Si-based aluminum alloy brazing material into a two layer structure such that a first layer brazing material is provided on the surface layer side and a second layer brazing material is provided on the core material side. The core material includes an aluminum alloy containing 0.1-1.3% Mg, the brazing material includes an Al-Si-based aluminum alloy containing 6-13% Si, and a Cs-containing fluoride flux including 5-60 mol% CsF and the balance of K-Al-F-based compound is incorporated in the interface between the first layer brazing material and the second layer brazing material, and a part or the whole of the flux is melted and then solidified. When assuming the amount of Mg contained in the core material as x (%), and the thickness of the second layer brazing material as y (mm), the amount of Mg contained in the core material and the thickness of the second layer brazing material satisfies a relation: y (mm)≥0.007 ln(x)+0.020 (ln is a natural logarithm).