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.

A clad aluminum alloy material exhibiting favorable corrosion resistance and brazeability in an alkaline environment is shown by a clad aluminum alloy material with excellent brazeability and corrosion resistance in which one surface of an aluminum alloy core material is clad with a sacrificial anode material and the other surface is clad with brazing filler material. The core material includes an aluminum alloy of Si: 0.3-1.5%, Fe: 0.1-1.5%, Cu: 0.2-1.0%, Mn: 1.0-2.0%, and Si content+Fe content 0.8%, wherein the 1-20 m equivalent circle diameter AlMnSiFe-based intermetallic compound density is 3.010.sup.5 to 1.010.sup.6 pieces/cm.sup.2, and the 0.1m to less than 1m equivalent circle diameter AlMnSiFe-based intermetallic compound density is at least 1.010.sup.7pieces/cm.sup.2. The sacrificial anode material includes an aluminum alloy containing Si: 0.1-0.6%, Zn: 1.0-5.0%, and Ni: 0.1-2.0%.

The present disclosure relates generally to an improved design of a metal-cored welding wire electrode for use on a high deposition rate welding process that resistively preheats the wire prior to being subjected to the welding current. The preheat circuit reduces the welding current drawn by the electrode so that higher wire feed speeds, and thus higher deposition rates, may be obtained. The metal-cored welding wire includes both a higher fill rate (a greater percentage of the welding wire is the granular core) along with added sulfur and an added bead wetting agent. The bead wetting agent may be one or more of selenium, tellurium, arsenic, gallium, bismuth, and tin. The improved metal-cored welding wire leads to an enhanced weld deposit appearance that means the weld deposits are less likely to be rejected as unusable.