Structural and microstructural study of nanostructured Fe50Al40Ni10 powders produced by mechanical alloying

A nanostructured Fe50Al40Ni10 mixture was prepared by mechanical alloying of elemental Fe, Al and Ni powders in a planetary ball mill. Structural and microstructural changes during the milling process were followed by X-ray diffraction technique. The patterns so obtained were analyzed using the Maud program. An ordered B2 FeAl phase is formed after 1 h of milling. The observed lattice expansion is related to the production of antisite defects; Fe-Al and Ale. During the intermediate stages of milling, the mechanical alloying process gives rise to a mixture of two BCC alpha-Fe(Al,Ni) (i=1,2) structures with the same crystallite size but different lattice parameters, microstrains and proportions. The BCC alpha(2)-Fe(Al,Ni) disappeared after 4 h, only the B2 FeAl and BCC alpha(1)-Fe(ALNi) solid solution persist over prolonged milling times. (C) 2011 Elsevier Inc. All rights reserved.