A study on the formation of iron aluminide (FeAl) from elemental powders

Summary, in English

The formation of iron aluminide (FeAl) during the heating of Fe-40 at.% Al powder mixture has been studied using a differential scanning calorimeter. The effect of particle size of the reactants, compaction of the powder mixtures as well as the heating rate on combustion behavior has been investigated. On heating compacted discs containing relatively coarser iron powder, DSC data show two consecutive exothermic peaks corresponding to precombustion and combustion reactions. The product formed during both these reactions is Fe2Al5 and there is a volume expansion in the sample. The precombustion reaction could be improved by a slower heating rate as well as a better surface coverage of iron particles using relatively finer aluminum powder. The combustion reaction was observed to be weaker after a strong precombustion stage. Heating the samples to 1000 degrees C resulted in the formation of a single and stable FeAl phase through the diffusional reaction between Fe2Al5 and residual iron. DSC results for compacted discs containing relatively finer iron powder and for the non-compacted samples showed a single combustion exotherm during heating, with Fe2Al5 as the product and traces of FeAl. X-ray diffraction and EDS data confirmed the formation of FeAl as the final product after heating these samples to 1000 degrees C. (C) 2015 Elsevier B.V. All rights reserved.

• Author: Hossein Sina; J. Corneliusson; Krystof Turba; Srinivasan Iyengar
• Department/s: Materials Engineering
• Publishing year: 2015
• Language: English
• Pages: 261-269
• Publication/Series: Journal of Alloys and Compounds
• Volume: 636
• Links: http://dx.doi.org/10.1016/j.jallcom.2015.02.132
• Document type: Journal article
• Publisher: Elsevier
• Topic: Materials Engineering
• Keywords: Iron aluminide; Intermetallics; Ignition reaction; DSC; Onset; temperature
• Status: Published
• ISBN/ISSN/Other: ISSN: 0925-8388