Structural characterization of AA 2024-MoSi2 nanocomposite powders produced by mechanical milling
来源期刊：International Journal of Minerals Metallurgy and Materials2013年第3期
论文作者：Mahmood Sameezadeh Hassan Farhangi Massoud Emamy
文章页码：298 - 306
摘 要：Nano-sized MoSi2 powder was produced successfully from commercially available MoSi2 by a mechanical milling process carried out for 100 h, and mechanical alloying was employed to synthesize AA 2024-MoSi2 nanocomposites. The effects of MoSi2 reinforcement and mechanical milling on the structure, morphology, and iron contamination of the produced materials were investigated using X-ray diffraction, scanning electron microscopy, and atomic absorption spectrometry. It is revealed that the morphology of the aluminum alloy changes continuously during milling from spherical to plate-like, irregular, and finally equiaxed. The presence of MoSi2 reinforcement accelerates the milling process and results in a smaller average particle size. The Williamson-Hall method determined that the crystallite size of the aluminum alloy in the composite powder is smaller than that of the unreinforced alloy at the same milling time and this size reaches 45 nm after 16 h milling time. The Fe contamination content is higher for the nanocomposite in comparison with the unreinforced alloy because of the wearing role of MoSi2 hard particles.
Mahmood Sameezadeh，Hassan Farhangi，Massoud Emamy
Center of Excellence for High Performance Materials, School of Metallurgy and Materials, College of Engineering, University of Tehran
摘 要：Nano-sized MoSi2 powder was produced successfully from commercially available MoSi2 by a mechanical milling process carried out for 100 h, and mechanical alloying was employed to synthesize AA 2024-MoSi2 nanocomposites. The effects of MoSi2 reinforcement and mechanical milling on the structure, morphology, and iron contamination of the produced materials were investigated using X-ray diffraction, scanning electron microscopy, and atomic absorption spectrometry. It is revealed that the morphology of the aluminum alloy changes continuously during milling from spherical to plate-like, irregular, and finally equiaxed. The presence of MoSi2 reinforcement accelerates the milling process and results in a smaller average particle size. The Williamson-Hall method determined that the crystallite size of the aluminum alloy in the composite powder is smaller than that of the unreinforced alloy at the same milling time and this size reaches 45 nm after 16 h milling time. The Fe contamination content is higher for the nanocomposite in comparison with the unreinforced alloy because of the wearing role of MoSi2 hard particles.
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