Amorphous and nanostructured AI-Fe-Nd powders obtained by gas atomization

In this work, an Al90Fe5Nd5 alloy was atomized and its microstructure, ther mal 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 mum size range. With thermal treatments the material evolved through three exot hermic reactions, which involved the formation of a nanostructured state Fe - and Nd-enriched amorphous matrix + fcc-Al nanocrystals at 240 degreesC, t he formation of a metastable ternary phase at 360 degreesC and, finally, th e formation of the equilibrium Al10Fe2Nd and Al11Nd3 phases. The high therm al stability of the amorphous + fcc-Al nanostructured state, 120 degreesC, and the high hardness, 280 Hv, of this alloy make it a good candidate for c onsolidate bulk material for technological applications. (C) 2001 Elsevier Science B.V. All rights reserved.