A method for manufacturing a heat exchanger (1) includes joining an inner fin (3) to a hollow structure (20) formed from at least two clad plates (200a, 200b) by heating and brazing a filler metal layer (B). Each clad plate has a core layer (A) composed of an aluminum alloy that contains Mg: 0.40-1.0 mass %. The filler metal layer is composed of an aluminum alloy that contains Si: 4.0-13.0 mass %, and further contains Li: 0.0040-0.10 mass %, Be: 0.0040-0.10 mass %, and/or Bi: 0.01-0.30 mass %. The inner fin is composed of an aluminum alloy that contains Si: 0.30-0.70 mass % and Mg: 0.35-0.80 mass %. A flux (F) that contains cesium (Cs) is applied along a contact part (201), and the vicinity thereof, of the at least two clad plates prior to the heating. A heat exchanger (1) may be manufactured according to this method.

There is provided the use of at least one ionic liquid as a soldering/brazing flux. There is also provided a method of soldering a metal comprising applying a solder/braze comprising a flux to a surface of the metal and heating said metal to a desired soldering/brazing temperature, wherein the soldering/brazing flux comprises one or more ionic liquids.

Disclosed is a method for activating a surface of metals, such as self-passivated metals, and of metal-oxide dissolution, effected using a fluoroanion-containing composition. Also disclosed is an electrochemical cell utilizing an aluminum-containing anode material and a fluoroanion-containing electrolyte, characterized by high efficiency, low corrosion, and optionally mechanical or electrochemical rechargeability. Also disclosed is a process for fusing (welding, soldering etc.) a self-passivated metal at relatively low temperature and ambient atmosphere, and a method for electrodepositing a metal on a self-passivated metal using metal-oxide source.

A purpose of the present invention is to provide a flux-cored wire that excels in slag removability and weldability, and is capable of high-efficiency operation without the risk of reheat cracking and makes it possible to obtain a welding bead with high corrosion resistance even when used in equipment operating at high temperature for a long time. The present invention relates to a flux-cored wire for gas-shielded arc welding that is used for welding using a specific shielding gas having a high Ar ratio, includes substantially no As, Sb, Pb and Bi, has slag component and alloy component compositions satisfying predetermined conditions, and satisfies the relationship {(3O.sub.2)+CO.sub.2+(0.0085A.sup.2)(0.19A)}20.0 (where A={Cr+(4.3Nb)}).

The invention described herein pertains generally to a process for making boric acid free flux compositions in which boric acid and/or borax is substituted with a molar equivalent amount of potassium tetraborate tetrahydrate. In some embodiments, a phthalocyanine pigment is used to affect a color change at activation temperature.

The invention described herein pertains generally to boric acid free flux composition in which boric acid and/or borax is substituted with a molar equivalent amount of potassium tetraborate tetrahydrate. In some embodiments, a phthalocyanine pigment is used to effect a color change at activation temperature.

The disclosed technology generally relates to welding, and more particularly to a consumable electrode wire for metal arc welding, and a method and a system for metal arc welding using the consumable electrode wire. In one aspect, a consumable welding wire configured to serve as an electrode during metal arc welding comprises one or more alkaline earth metal elements at a concentration between 0.005% and 10% on the basis of a total weight of the welding wire.

Disclosed is a method for activating a surface of metals, such as self-passivated metals, and of metal-oxide dissolution, effected using a fluoroanion-containing composition. Also disclosed is an electrochemical cell utilizing an aluminum-containing anode material and a fluoroanion-containing electrolyte, characterized by high efficiency, low corrosion, and optionally mechanical or electrochemical rechargeability. Also disclosed is a process for fusing (welding, soldering etc.) a self-passivated metal at relatively low temperature and ambient atmosphere, and a method for electrodepositing a metal on a self-passivated metal using metal-oxide source.

A process for brazing of aluminium magnesium alloys is described applying a flux which comprises KAlF.sub.4 or CsAlF.sub.4 or both as major constituent. The flux further comprises at least one alkaline or alkaline earth metal compound selected from the group consisting of KAlF.sub.4, CsAlF.sub.4, Li.sub.3AlF.sub.6, CaF.sub.2, CaCO.sub.3, MgF.sub.2, MgCO.sub.3, SrF.sub.2, SrCO.sub.3, BaF.sub.2, and BaCO.sub.3. Preferably the flux comprises or consists of KAlF.sub.4, CsAlF.sub.4, and Li.sub.3AlF.sub.6 and optionally contains also BaF.sub.2.

Described herein are compositions for use in the brazing of metal substrates. Methods of making and using these compositions are also described herein.