Low melting temperature flux materials for brazing applications and methods of brazing using the same are provided. A low melting temperature flux material for brazing applications includes as a majority constituent, a Cs-containing flux material, as a first minority constituent, a eutectic blend composition, and, optionally, as a second minority constituent, a mediating compound. The second minority constituent is present in the low melting temperature flux material in a lesser amount with respect to the first minority constituent.

A method of welding including: applying a flux having at least a majority weight percent boron to a surface of a superalloy base material; forming a weldment on the surface wherein boron is melted onto the surface and is incorporated into a resulting weld pool and heat affected zone, and wherein incipient melted inter-dendritic material resulting from presence of the boron is available to flow into a crack formed during cooling of the weldment; and heat treating the weldment to diffuse a remaining concentration of the boron in the weldment and heat affected zone to a desired value.

A method for joining a first metal part with a second metal part, the metal parts having a solidus temperature above 1100° C., includes applying a melting depressant composition on a surface of the first metal part, the melting depressant composition including a melting depressant component that includes at least 25 wt % boron and silicon for decreasing a melting temperature of the first metal part; bringing the second metal part into contact with the melting depressant composition at a contact point on said surface; heating the first and second metal parts to a temperature above 1100° C.; and allowing a melted metal layer of the first metal component to solidify, such that a joint is obtained at the contact point. The boron at least partly originates from a boron compound selected from any of the following compounds: boric acid, borax, titanium diboride and boron nitride. The melting depressant composition and related products are also described.

A method for joining a first metal part with a second metal part, the metal parts having a solidus temperature above 1100° C., includes applying a melting depressant composition on a surface of the first metal part, the melting depressant composition including a melting depressant component that includes at least 25 wt % boron and silicon for decreasing a melting temperature of the first metal part; bringing the second metal part into contact with the melting depressant composition at a contact point on said surface; heating the first and second metal parts to a temperature above 1100° C.; and allowing a melted metal layer of the first metal component to solidify, such that a joint is obtained at the contact point. The boron at least partly originates from a boron compound selected from any of the following compounds: boric acid, borax, titanium diboride and boron nitride. The melting depressant composition and related products are also described.

The invention concerns a flux for brazing, a process for brazing metal parts employing said flux, a flux composition containing said flux, aluminum parts coated with said flux or said flux composition, a process for brazing and a brazed metal object obtainable by said brazing process. The flux is high in KAlF.sub.4 and low in K.sub.3AlF.sub.6.

A universal approach is described to produce welding filler materials with enhanced grain refining, for making welded objects with hot-crack resistance. Some variations provide a welding filler material comprising a functionalized metal-containing powder, wherein the functionalized metal-containing powder comprises metal or metal alloy particles and a plurality of nanoparticles disposed on surfaces of the metal or metal alloy particles, and wherein the nanoparticles are consolidated in a three-dimensional architecture throughout the welding filler material. A welded object contains a welding filler material comprising the functionalized metal-containing powder, enabling the welded object to be free of hot cracks. Other variations provide methods of making a welding filler material. This approach has been successfully demonstrated by incorporating zirconium-based nanoparticle grain refiners within a welding precursor material for welding aluminum alloy Al 7075, as one non-limiting example.

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.

A metallic structure defines ribs and a skin supported by the ribs. The ribs may be defined by metal strips and the skin may be attached to the ribs. Alternatively, the skin may be defined by a plurality of tiles and the ribs may be defined by flanges of each of the plurality of tiles that cooperate to define the ribs. Tiles may be attached to separate rib lattice. Structurally weak locations at nodes where ribs intersect may be reinforced. The components may be brazed together and the stiffness of adjacent locations in the structure adjusted in the brazing operation to reduce the difference in stiffness and to reduce resulting stress risers. The metallic structure may be armored using metal foam to absorb the energy of a projectile.

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.