Mitsubishi Aluminum Company, Ltd.

Yuji Nomura

Hideyuki Miyake

Masakazu Edo

Hiroki Amano

Norihiro Nose

Masatoshi Akiyama

In order to enable a satisfactory fluxless brazing without needing flux or vacuum facilities, a brazing object including an aluminum alloy material provided with an Al&#x2014;Si&#x2014;Mg brazing filler metal is joined by the Al&#x2014;Si&#x2014;Mg brazing filler metal without the use of flux by heating the aluminum alloy material, when raising the temperature in a brazing furnace, at least in a temperature range of 450&#xb0; C. to before melting of the filler metal under a first inert gas atmosphere having an oxygen concentration of preferably 50 ppm and following by heating at least at or above a temperature at which the filler metal starts to melt under a second inert gas atmosphere having an oxygen concentration of preferably 25 ppm and a nitrogen gas concentration of preferably 10% by volume or less. The oxygen concentration and nitrogen concentration in the atmosphere in the course of brazing are controlled in this way, whereby the reliability of a joint is remarkably improved, compared with conventional fluxless brazing methods, while suppressing cost increases as much as possible.

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Tokyo, Japan

Yuji Nomura