FLUXLESS BRAZING METHOD FOR ALUMINUM MATERIAL

To provide a fluxless brazing method for aluminum material capable of obtaining a sufficient getter action by Mg in a brazing material to form a favorable brazing part.SOLUTION: An objective brazing method includes: a vacuum heating process of heating a brazing assembly which includes a first member to be brazed made by an aluminum material, a second member to be brazed and an Al-Mg-Si based alloy brazing material including Mg of 0.1-3.0 mass% in the temperature range from 380 to 520°C in a furnace whose inside is made to be in a vacuum state by evacuation; a process of stopping the evacuation; a process of setting the pressure in the furnace to 3×10Pa or more by introducing an inert gas in the furnace in such a state as maintaining the evacuation stop state and also in such a state that the temperature of the brazing material is lower than the starting temperature of the material melting; and a process of brazing by heating the brazing material in an inert gas atmosphere under the in-furnace pressure of 3×10Pa or more in such a state as maintaining the evacuation stop state to melt the brazing material.SELECTED DRAWING: Figure 4 【課題】ろう材中のＭｇによるゲッター作用が十分に得られて良好なろう付部を形成できる、アルミニウム材のフラックスレスろう付方法を提供する。【解決手段】アルミニウム材製の第１被ろう付部材と、第２被ろう付部材と、Mg：0.1質量％〜3.0質量％を含有するAl-Mg-Si系合金ろう材と、を含むろう付用組み付け体が中に配置された炉の内部を真空排気により真空状態にした炉内で組み付け体の温度が380℃〜520℃の範囲になるように加熱を行う真空加熱工程と、前記真空排気を停止する工程と、真空排気停止状態を維持した状態で、かつろう材の温度が該ろう材の溶融開始温度より低い状態下で炉内に不活性ガスを導入して炉内圧力を3×103Ｐａ以上に設定する工程と、真空排気停止状態を維持した状態でかつ3×103Ｐａ以上の炉内圧力下の不活性ガス雰囲気中で加熱を行ってろう材を溶融させてろう付を行う工程と、を含むろう付方法とする。【選択図】図４