Synthesis of titanium diboride reinforced alumina matrix nanocomposite by mechanochemical reaction of Al-TiO2-B2O3

In order to produce alumina matrix nanocomposite reinforced by titanium diboride, a mixture of titanium oxide, boron oxide and aluminum powders was subjected to high-energy ball milling. The structural evaluation of powder particles after different milling times was studied by X-ray diffractometry, scanning electron microscopy and transmission electron microscopy. The results showed that after 60 h of milling the Al/TiO2/B2O3 reacted with a self-propagating combustion mode and an alumina matrix nanocomposite containing titanium diboride particulate was formed. In final stage of milling, the crystallite size of alumina and titanium diboride were calculated to be less than 50 nm. No phase change observed after annealing treatment of the synthesized nanocomposite powders. The formation mechanism of this nanocomposite was investigated. (C) 2010 Elsevier B.V. All rights reserved.