BRAZING SHEET FOR FLUX-FREE BRAZING, FLUX-FREE BRAZING METHOD AND FLUX-FREE BRAZING METHOD FOR HEAT EXCHANGER

摘要

PROBLEM TO BE SOLVED: To provide a flux-free brazing sheet and brazing method, capable of brazing an aluminum member in a favorable joint state.SOLUTION: A brazing sheet for flux-free brazing is characterized in that an outermost surface brazing material layer comprising an Al-Si alloy including 4-12 mass% of Si, and an intermediate brazing material layer comprising an Al-Si-Mg alloy including 1-4 mass% of Si and 0.1-5.0 mass% of Mg are clad on one side or both sides of a core material. The aluminum members are joined to each other using the brazing sheet under a normal pressure of the oxygen concentration of 300 ppm or less in a non-oxidizing gas atmosphere without using a flux.SELECTED DRAWING: Figure 1