Study on the structure and properties of core–shell Fe/Al composite powder synthesized by MOCVD in fluidized bed

• Core–shell Fe/Al composite powder with uniform and compact Fe coating layer has been successfully prepared.
• The thickness of Fe layer can be controlled by adjusting deposition time.
• Combustion properties of Fe/Al composite powder have great improvement compared with raw Al.

Core–shell Fe/Al composite powder with different thicknesses of Fe layer has been prepared by MOCVD in a fluidized bed reactor. The products were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDX) and simultaneous thermogravimetry–differential scanning calorimetry (TG–DSC). The results show that a compact nano-Fe layer is covered on the surface of Al to form core–shell Fe/Al composite powder. Nano-Fe layer thickness can be controlled by adjusting deposition time. The Fe layer thickness is evaluated by weight increase in TG curve at the temperature range of 350–550 °C in air atmosphere. Combustion properties of Fe/Al composite powder have great improvement compared with raw Al.

Nearly every Al particle is coated by a layer of Fe. At a higher magnification image, the outer Fe layer has a very uniform layer thickness and is coated on Al compactly. Different deposition time has been adopted to change the thickness of Fe layer, the variation of Fe layer thickness can be revealed apparently in the TG–DSC curves.Figure optionsDownload as PowerPoint slide