Abstract: A composition for brazing aluminum or aluminum alloy characterized in that said composition contains aluminum alloy powder for brazing and thermoplastic acryl-based resin binder which is so volatile as to volatilize before being carbonized at a brazing temperature and said resin binder of 0.1 to 50 parts is used for aluminum alloy powder of 100 parts. When this technological idea was applied to brazing with a brazing material of aluminum alloy powder such as, for example, Al-Si, a preferable result of brazing could be obtained.

Abstract: A method of producing a heat exchanger comprising abutting a tube made of an aluminum material and fins made of an aluminum material, applying to the resulting abutments a flux containing zinc halide, and thereafter conducting a reaction soldering in an inert gas atmosphere. The assembled tube and fins applied with the flux may be moved in a position to enhance the formation of zinc deposited by the reaction soldering during the drying step of the flux. The heat exchanger produced by this method has a thick and uniform Zn coating at the joints with good mechanical strength and surface conditions.

Abstract: A brazed aluminum article comprising at least two aluminum members brazed together with a filler metal, which consists essentially of:zinc: from 20 to 80 wt. %,silicon: from 1 to 11 wt. %, andthe balance being aluminum and incidental impurities.The above-mentioned filler metal may further additionally contain copper within the range of from 0.1 to 10 wt. %. The ratio of the silicon content to the aluminum content in the above-mentioned filler metal should preferably be within the range of from 0.05 to 0.12.

Abstract: A method of producing a heat exchanger comprising abutting a tube made of an aluminum material and fins made of an aluminum material, applying to the resulting abutments a flux containing zinc halide, and thereafter conducting a reaction soldering in an inert gas atmosphere. The assembled tube and fins applied with the flux may be moved into a position to enhance the formation if zinc deposited by the reaction soldering during the drying step of the flux. The heat exchanger produced by this method has a thick and uniform Zn coating at the joints with good mechanical strength and surface conditions.

Abstract: An aluminum alloy sheet as a fin material for tubes of a heat exchanger, excellent in high-temperature sagging resistance and sacrificial anode property and having a high room-temperature strength, which consists essentially of:Manganese: from 0.95 to 1.50 wt. %,silicon: from 0.5 to 1.2 wt. %,zinc: from 0.1 to 2.0 wt. %,at least one element selected from the group consisting of:copper: from 0.05 to 0.60 wt. %, andmagnesium: from 0.05 to 0.60 wt. %, where, the total amount of said copper and said magnesium being up to 1.0 wt. %, andthe balance being aluminum and incidental impurities.the above-mentioned aluminum alloy sheet may further additionally contain at least one element selected from the group consisting of:chromium: from 0.03 to 0.30 wt. %, andzirconium: from 0.03 to 0.15 wt. % where, the total amount of said chromium and said zirconium being up to 0.4 wt. %.

Abstract: A clad sheet comprising an aluminum alloy sheet having excellent high-temperature sagging resistance and thermal conductivity comprising an aluminum alloy sheet clad on at least one surface with a brazing metal, said aluminum alloy sheet consists essentially of:manganese: from 0.1 to 0.5 wt. %,silicon: from 0.1 to 0.8 wt. %,zirconium: from 0.02 to 0.2 wt. %,and, the balance being aluminum and incidental impurities.The clad sheet is particularly adapted to be used as a fin material for tubes of a heat exchanger, said aluminum alloy sheet may also contain chromium within the range of from 0.05 to 0.4 wt. % and/or at least one element selected from the group consisting of:magnesium: from 0.1 to 0.7 wt. %, and,copper: from 0.1 to 0.7 wt. %,total amount of said magnesium and said copper being up to 1.0 wt. %.