A heat exchanger is disclosed. The heat exchanger includes a hollow tube extending from a tube inlet to a tube outlet. The hollow tube includes a wall that includes a core of a first aluminum alloy, and a cladding over the core of a second aluminum alloy. The second aluminum alloy is less noble than the first aluminum alloy and includes an alloying element selected from tin, indium, or gallium, or combinations thereof. A first fluid flow path is disposed along an inner surface of the wall from the tube inlet to the tube outlet, and a second fluid flow path is disposed across an outer surface of the wall.

A device for manufacturing a plate solder according to the present invention includes a reel on which a thread solder is wound; a cutter that cuts the thread solder, provided between the reel and an end part of the thread solder extending from the reel; an aggregating part that aggregates a plurality of cut thread solders such that the plurality of thread solders are in contact with one another; and a roller that rolls the plurality of aggregated thread solders and pressure bonds them to one another to form a plate solder.

A device for manufacturing a plate solder according to the present invention includes a reel on which a thread solder is wound; a cutter that cuts the thread solder, provided between the reel and an end part of the thread solder extending from the reel; an aggregating part that aggregates a plurality of cut thread solders such that the plurality of thread solders are in contact with one another; and a roller that rolls the plurality of aggregated thread solders and pressure bonds them to one another to form a plate solder.

A brazing sheet (1) includes a core material (11) composed of an Al alloy that contains 0.20-3.0 mass % of Mg; and a filler material (12) layered on the core material and composed of an Al alloy that contains Mg, 6.0-13.0 mass % of Si, and more than 0.050 mass % and 1.0 mass % or less of Bi. The Mg concentration of the filler material becomes continuously lower in a direction from a boundary (122) with the core material to an outermost surface (121). The Mg concentration of the filler material is 0.150 mass % or less at a first depth from the outermost surface that is ⅛ of a thickness (t.sub.f) of the filler material and is 5-90% of the amount of Mg in the core material at a second depth from the outermost surface that is ⅞ of the thickness of the filler material.

A brazing sheet (1) includes a core material (11) composed of an Al alloy that contains 0.20-3.0 mass % of Mg; and a filler material (12) layered on the core material and composed of an Al alloy that contains Mg, 6.0-13.0 mass % of Si, and more than 0.050 mass % and 1.0 mass % or less of Bi. The Mg concentration of the filler material becomes continuously lower in a direction from a boundary (122) with the core material to an outermost surface (121). The Mg concentration of the filler material is 0.150 mass % or less at a first depth from the outermost surface that is ⅛ of a thickness (t.sub.f) of the filler material and is 5-90% of the amount of Mg in the core material at a second depth from the outermost surface that is ⅞ of the thickness of the filler material.

Provided is a low-density clad steel sheet having excellent formability and fatigue properties, including a base material; and cladding materials provided on both side surfaces of the base material, wherein the base material is a lightweight steel sheet including, by weight, C: 0.3 to 1.0%, Mn: 4.0 to 16.0%, Al: 4.5 to 9.0%, and a remainder of Fe and inevitable impurities, and each of the cladding materials is martensitic carbon steel including, by weight, C: 0.1 to 0.45%, Mn: 1.0 to 3.0%, and a remainder of Fe and inevitable impurities.

Provided is a low-density clad steel sheet having excellent formability and fatigue properties, including a base material; and cladding materials provided on both side surfaces of the base material, wherein the base material is a lightweight steel sheet including, by weight, C: 0.3 to 1.0%, Mn: 4.0 to 16.0%, Al: 4.5 to 9.0%, and a remainder of Fe and inevitable impurities, and each of the cladding materials is martensitic carbon steel including, by weight, C: 0.1 to 0.45%, Mn: 1.0 to 3.0%, and a remainder of Fe and inevitable impurities.

An aluminum alloy brazing sheet used for brazing in an inert gas atmosphere without using flux includes a core material of aluminum or aluminum alloy, and a brazing material of aluminum alloy including Si of 4.0 mass % to 13.0 mass % and cladding one side surface or both side surfaces of the core material. One or both of the core material and the brazing material includes any one or two or more types of X atoms (X is Mg, Li, Be, Ca, Ce, La, Y, and Zr). The aluminum alloy brazing sheet is a brazing sheet in which oxide particles including the X atoms and having a volume change ratio of 0.99 or lower with respect to an oxide film before brazing heating are formed on a surface thereof, by brazing heating.

An aluminum alloy brazing sheet used for brazing in an inert gas atmosphere without using flux includes a core material of aluminum or aluminum alloy, and a brazing material of aluminum alloy including Si of 4.0 mass % to 13.0 mass % and cladding one side surface or both side surfaces of the core material. One or both of the core material and the brazing material includes any one or two or more types of X atoms (X is Mg, Li, Be, Ca, Ce, La, Y, and Zr). The aluminum alloy brazing sheet is a brazing sheet in which oxide particles including the X atoms and having a volume change ratio of 0.99 or lower with respect to an oxide film before brazing heating are formed on a surface thereof, by brazing heating.

A method of creating a clad metal part is provided. The method includes explosion bonding a plate comprised of a base layer and an interlayer. The explosion bonded plate is then cut into bars which are roll bonded with a clad layer. Ultimately a part is fabricated from the roll bonded bar. The solution enables parts to have material combinations and resulting physical properties more optimal for an application than a single bonding process.