Microstructure and mechanical properties of MgO-doped Al 2TiO5 prepared by reactive sintering

Abstract

MgO-doped Al2TiO5 ceramics were reactively sintered from commercial α-Al2O3, TiO2 anatase and MgCO3 (basic) powders. Powder mixtures with molar ratio of Al2O 3:TiO2:MgO = 1:1:0, 1:0.95:0.05, 1:0.90:0.10, and 1:0.85:0.15 were prepared by wet ball-milling with ZrO2 media. The green pellets were sintered at 1300-1500°C for 2h in air to obtain dense samples. With changing the MgO doping amount, Al2TiO 5/Al2O3, Al2TiO5/MgAl 2O4/Al2O3, Al2TiO 5/MgAl2O4composites were synthesized. MgO doping was effective to reduce the Al2TiO5matrix grain size and to reduce the strong anisotropy of Al2TiO5, which resulted in fewer microcracks. The maximum strength of samples sintered at 1400 and 1500°C were 106 and 32MPa (15 mol% MgO), respectively. ©2013 The Ceramic Society of Japan. All rights reserved.