Amorphous and nanostructured Al–Fe–Nd powders obtained by gas atomization

In this work, an Al90Fe5Nd5 alloy was atomized and its microstructure, thermal stability, transformation sequence and microhardness investigated as a function of powder particle size. The atomized powder contained on average a 25% volume fraction of amorphous materials, reaching 42% in the <25 μm size range. With thermal treatments the material evolved through three exothermic reactions, which involved the formation of a nanostructured state Fe- and Nd-enriched amorphous matrix+fcc-Al nanocrystals at 240°C, the formation of a metastable ternary phase at 360°C and, finally, the formation of the equilibrium Al10Fe2Nd and Al11Nd3 phases. The high thermal stability of the amorphous+fcc-Al nanostructured state, 120°C, and the high hardness, 280 Hv, of this alloy make it a good candidate for consolidate bulk material for technological applications.