Frontiers of Chemical Science and Engineering
>> 2013,
Volume 7,
Issue 2
doi:
10.1007/s11705-013-1325-6
RESEARCH ARTICLE
Events and reaction mechanisms during the synthesis of an Al
1. Materials Engineering Department, Islamic Azad University, Saveh Branch, Saveh Iran; 2. Ceramic Department, Materials and Energy Research Center, Tehran 31787/316, Iran; 3. Chemical engineering and Materials Science Department, University of California, Davis, CA 95616, USA
Available online: 2013-06-05
Next
Previous
Abstract
An Al O -TiB nanocomposite was successfully synthesized by the high energy ball milling of Al, B O and TiO . The structures of the powdered particles formed at different milling times were evaluated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Thermodynamic calculations showed that the composite formed in two steps via highly exothermic mechanically induced self-sustaining reactions (MSRs). The composite started to form at milling times of 9–10 h but the reaction was not complete. The remaining starting materials were consumed by increasing the milling time to 15 h. The XRD patterns of the annealed powders showed that aluminum borate is one of the intermediate products and that it is consumed at higher temperatures. Heat treatment of the 6-h milled sample at 1100 C led to a complete formation of the composite. Increasing the milling time to 15 h led to a refining of the crystallite sizes. A nanocomposite powder with a mean crystallite size of 35–40 nm was obtained after milling for 15 h.
京公网安备 11010502051620号
