An aluminum alloy brazing sheet is formed of a four-layer material formed of a brazing material, an intermediate material, a core material, and a brazing material. The intermediate material comprises Mg of 0.40 to 6.00 mass %, and has a total of contents of Mn, Cr, and Zr being 0.10 mass % or more. The core material comprises Mg of 0.20 to 2.00 mass % and comprises one or two or more of Mn of 1.80 mass % or less, Si of 1.05 mass % or less, Fe of 1.00 mass % or less, Cu of 1.20 mass % or less, Ti of 0.30 mass % or less, Zr of 0.30 mass % or less, and Cr of 0.30 mass % or less. Each of the core material and the intermediate material has a grain size of 20 to 300 μm.

An aluminum brazing sheet for flux-free brazing having a multilayer structure of two or more layers including at least one core material layer and one brazing material layer, wherein the brazing material layer is positioned on one or both sides of the core material layer and on an outermost surface of the brazing sheet. The brazing material layer is made of an Al—Si—Mg—X brazing material containing: in mass%, 0.05 to 2.0% of Mg, and 2.0 to 14.0% of Si, and further containing one or more of 0.01 to 0.3% of Bi, Ga, Sn, In and Pb, a total amount of Bi, Ga, Sn, In and Pb being 0.5% or less. X indicates one or more of Bi, Ga, Sn, In and Pb.

An aluminum alloy brazing sheet used for brazing in an inert gas atmosphere without using a flux includes a brazing material cladded onto at least one side surface of a core material. An oxide is formed on a surface of the aluminum alloy brazing sheet by brazing heating, the oxide including any one or two or more of Mg, Li, and Ca and having a volume change ratio of 0.990 or less to a surface oxide film formed before brazing heating, and an atomic molar ratio of Mg, Li, and Ca to Al in the oxide formed on the surface of the aluminum alloy brazing sheet before brazing heating is 0.50 or less. The present invention provides an aluminum alloy brazing sheet having excellent brazability in brazing in an inert gas atmosphere without using a flux, and a method for manufacturing the same.

A closed impeller (1) includes an impeller main body (2), which is composed of an aluminum alloy and has blades (22) that protrude from a hub (21). A shroud (3) covers the blades. The blades and the shroud are joined together by brazed joints (4). The shroud (3) is formed from a brazing sheet (30) that comprises a core material (31), which is composed of an aluminum alloy, and a filler material layer (320), which is disposed on an outermost surface (33) of the shroud that opposes or faces the blades when the shroud is brazed to the blades.

A bonded body of the present invention includes a ceramic member formed of ceramics and a Cu member formed of Cu or a Cu alloy. In a bonding layer formed between the ceramic member and the Cu member, an area ratio of a Cu.sub.3P phase in a region extending by up to 50 μm toward the Cu member side from a bonding surface of the ceramic member is equal to or lower than 15%.

An aluminum alloy brazing sheet is formed of a four-layer material formed of a brazing material, an intermediate material, a core material, and a. brazing material. The intermediate material comprises Mg of 0.40 to 6.00 mass %, and has a total of contents of Mn, Cr, and Zr being 0.10 mass % or more. The core material comprises Mg of 0.20 to 2.00 mass % and comprises one or two or more of Mn of 1.80 mass % or less, Si of 1.05 mass % or less, Fe of 1.00 mass % or less, Cu of 1.20 mass % or less, Ti of 0.30 mass % or less, Zr of 0.30 mass % or less, and Cr of 0.30 mass % or less. Each of the core material and the intermediate material has a grain size of 20 to 300 μm.

Provided is a solder-metal mesh composite material in which a lead-free solder layer formed of Sn—Cu—Ni-based lead-free solder contains metal mesh having high thermal conductivity, a void occupancy in a cross-section in a thickness direction is 15% or less, and the Sn—Cu—Ni-based lead-free solder contains 0.1 to 2% by weight of Cu, 0.002 to 1% by weight of Ni, and Sn as a remainder or contains 0.1 to 2% by weight of Cu, 0.002 to 1% by weight of Ni, 0.001 to 1% by weight of Ge, and Sn as a remainder.

New aluminum alloy brazing sheets are disclosed. The new aluminum alloy brazing sheets may include a core, an interliner layer adjacent the core, and a braze liner adjacent the interliner layer. The interliner layer may include a first aluminum alloy having at least 0.35 wt. % Si and from 0.05 to 2.0 wt. % Mg. The braze liner may include a second aluminum alloy having 0.05 to 2.0 wt. % Mg. The first aluminum alloy and the second aluminum alloy may include an amount of magnesium sufficient to achieve T.sub.solidus(IL)≥5° C. T.sub.liquidus(BL). The new aluminum alloy brazing products may be useful, for instance, in fluxfree brazing.

A sheet blank includes a core substrate having a generally planar shape with opposed first and second sides. The core substrate is made of high-strength steel containing at least two of ferrite, martensite, bainite, and austenite and having an ultimate tensile strength of at least 490 MPa. A respective decarburized layer of the high-strength steel is formed on each of the first and second sides of the core substrate, wherein each respective decarburized layer contains a minimum ferrite content of at least 80 volume % ferrite and has a respective thickness of 5 to 100 microns. A respective transition layer of the high-strength steel may be formed between the core substrate and each respective decarburized layer, with each transition layer having a respective inner transition layer abutting the core substrate and a respective outer transition layer abutting the respective decarburized layer.

A bonding material (10) of the present invention includes an amorphous silver film (12).