Structural direct-write additive manufacturing of molten metals

A method of fabricating a three-dimensional (3D) metallic object using direct-write additive manufacturing, the method comprising the steps of:

• a. providing an alloy comprising a base element selected from the group consisting of aluminum (Al), nickel (Ni) and a combination thereof, and a rare earth element selected from the group consisting of cerium (Ce), lanthanide (La) and a combination thereof, and a eutectic intermetallic present in said alloy in an amount ranging from about 0.5 wt. % to 7.5 wt. %;
• b. heating said alloy to a temperature within 15% above or below a melting point of said alloy in an inert atmosphere;
• c. extruding said alloy through a nozzle in the presence of an oxygen-containing atmosphere, including but not limited to ambient atmosphere, to form beads of said alloy having a surface tension ranging from about 0.3 N/m to 2.0 N/m, wherein before exiting said nozzle said alloy remains in said inert atmosphere, and a stabilizing shell is formed surrounding a liquid core of each of said beads when said beads are exposed to said oxygen-containing atmosphere, wherein said stabilizing shell comprises oxides of alloying elements of said alloy and at least one metastable intermetallic of the alloying elements;
• and
• d. depositing said beads on a substrate and contacting said beads with each other, wherein said stabilizing shells of adjacent beads fuse on contact as said beads are cooled down in said oxygen-containing atmosphere, wherein during the fusing of the beads, said eutectic intermetallic is formed at an interface of said adjacent beads in an amount greater than that within each of said adjacent beads.