Synthesis of ordered Al 3Nb intermetallic by mechanical alloying

Abstract

The solid-state powder processing technique of mechanical alloying (MA) has been employed to synthesize a variety of alloy phases starting from either blended elemental or prealloyed powders. These include supersaturated solid solutions, crystalline and quasicrystalline intermediate phases, and metallic glasses. Very often the crystalline phases produced have nanometer-sized grains. It has been shown earlier that a number of intermetallics can be synthesized either directly by MA or on subsequent heat treatment of mechanically alloyed powders starting from blended elemental powders. However, even those few examples when an intermetallic compound is synthesized directly by MA, the crystal structure has been found to be disordered. The authors report the first instance of synthesis of the ordered Al[sub 3]Nb compound directly by MA starting from blended elemental powders.