Ceramics-Silikáty 56, (1) 130 - 134 (2012)

Al₂O₃–TiC nanocomposite powder was successfully synthesized by ball milling TiO₂, Al and graphite powders. Effects of cup and ball type, milling time and annealing were investigated. XRD was used to characterize milled and annealed powders. The morphological and microstructural evolutions were studied by SEM and TEM. Results showed that the formation of this composite begins after 20 h and completes after 35 h of milling with stainless steel cup and balls. In contrast, there is no reaction during milling (up to 80 h) with ZrO₂ cup and balls. Fe and ZrO₂ were the major impurities introduced during milling with stainless steel and ZrO₂ cups, respectively. The Fe impurity was removed by leaching in 3HCl·HNO₃ solution for 4 days. Mean grain size less than 7 nm was achieved at the end of milling. In spite of grain growth, this composite maintained its nanocrystalline nature after annealing at 1000^oC.