Study On Preparation Of Fe/Al Composites By Chemical Liquid Deposition Method

High activity of micro/nano aluminum powder leads to the oxidation or spontaneouscombustion of its surface, which lose the combustion performance of micro/nanoaluminum powder. In this paper, with micro/nano aluminium powder as matrixes, Fe/Alcomposites were prepared by the chemical liquid deposition method in Ar atmosphere.The Fe/Al composites make Fe coating on Al particle which improved the combustionperformance ofAl powder.In this work, the effect of experimental technics conditions on the preparation of micronFe-coated Al composites was mainly discussed. Firstly, with the aluminum powder namedL3（average particle size is2μm） as matrix, Fe/Al composites were prepared by selectingthe molar ratio of Fe and Al as0.3:1,0.5:1and0.7:1, respectively. XRD and SEM havebeen employed to characterize Fe/L3composites. The results shows the coating effect forthe composites prepared with selecting0.5:1as the molar ratio of Fe and Al is best.TG-DTA test in O2of Fe/Al composites exhibits their good thermal property. Secondly,Fe/Al composites have been prepared using chemical liquid deposition method byinjecting Fe（CO）5at room temperature and180℃with aluminum powders of threeparticle sizes as matrixes. XRD and SEM have been employed to characterize theas-prepared samples. The results indicate that the aluminum particles are coated with ironand the coating effect varies with the particle size and injecting temperature of Fe（CO）5.Higher temperature （180℃）, is fit for large particle size, while the lower temperature （RT）,is better for small particle size. The interesting phenomenon indicates the differentnucleating process under different injecting temperature. In addition, based on thechemical liquid deposition method, the glass reaction kettle and peristaltic pumpequipments were used to prepare core-shell micron Fe/Al composite and realize the massproduction of this composite.Moreover, based on the praperation of core-shell micro Fe/Al composite, with nanoaluminum powder as matrix, Fe₃Al/Al core-shell nanoparticle was obtained by heattreatment of Fe-Al precursor prepared by the chemical liquid method in high purity ofargon. The TG-DSC measurements in compressed air （20%O2+80%N2） reveal that the heat-treated powder of the precursor remains thermal stability in relatively lowtemperature but becomes concentrated combustion in elevated temperature.