Preparation of Al₂TiO₅-Al₂O₃and Al₂TiO₅-Al₂O₃-TiO₂ Ceramics by High-Energy Ball Milling and Sintering

Abstract

The present work reports on the preparation of Al 2 O 3 -TiO 2 ceramics by high-energy ball milling and sintering, varying the molar fraction in 1:1 and 3:1. The powder mixtures were processed in a planetary Fritsch P-5 ball mill using silicon nitride balls (10 mm diameter) and vials (225 mL), rotary speed of 250 rpm and a ball-to-powder weight ratio of 5:1. Samples were collected into the vial after different milling times. The milled powders were uniaxially compacted and sintered at 1300 and 1500°C for 4h. The milled and sintered materials were characterized by X-ray diffraction and electron scanning microscopy (SEM). Results indicated that the intensity of Al 2 O 3 and TiO 2 peaks were reduced for longer milling times, suggesting that nanosized particles can be achieved. The densification of Al 2 O 3 -TiO 2 ceramics was higher than 98% over the relative density in samples sintered at 1500°C for 4h, which presented the formation of Al 2 TiO 5 .