Microstructure and Morphology of Alumina-Iron Nanocomposite Powders Produced by High Energy Mechanical Milling
Alumina-iron nanocomposite powders containing 5vol.% of iron were fabricated by high-energy ball milling with different ball-to-powder weight ratios (BPRs) as part of the study of ceramic-metal nanocomposite magnetic materials. The microstructure and morphology of the composite powders were characterized using the X-ray diffraction, optical microscopy and scanning electron microscopy. XRD analysis and SEM examination in combination with energy dispersive X-ray spectrometry confirmed that the nanocomposite structure of the powder particles formed only after 8 hours milling for both BPRs used. With a higher BPR of 16:1, Fe-Cr alloy material was broken from the stainless steel balls and incorporated into the nanocomposite powder. However, such a problem did not occur with a lower BPR of 5:1. The mechanism for formation of the alumina matrix nanocomposite powder is found to be dependent on BPR and milling time.
Deliang Zhang, Kim Pickering, Brian Gabbitas, Peng Cao, Alan Langdon, Rob Torrens and Johan Verbeek
M. Yusop et al., "Microstructure and Morphology of Alumina-Iron Nanocomposite Powders Produced by High Energy Mechanical Milling ", Advanced Materials Research, Vols. 29-30, pp. 131-134, 2007