Preparation, microstructure and properties of MgO modified Al2TiO5 porous ceramics

Abstract

Al2TiO5 porous ceramics with high density and excellent thermal stability were prepared by the replica template method. MgO was introduced into Al2TiO5 by adding magnesite (MgCO3) to the slurry during the preparation process. The density and compressive strength of Al2TiO5 porous ceramics with varying MgCO3 content were studied. Additionally, the atomic-scale microstructure, thermal stability, and thermal shock resistance of the Al2TiO5 porous ceramics with 2 wt% MgCO3 were investigated. The results show that the Al2TiO5 porous ceramics doped with 2 wt% MgCO3 exhibit the highest density and compressive strength. The crystallographic orientation relationships of Al2TiO5 (ATO) - Mg0.3Al1.4Ti1.3O5 (MATO) and Mg0.3Al1.4Ti1.3O5 (MATO) - MgAl2O4 (MAO) are observed as (1 1 3) ATO//(1 1 2) MATO and [1‾ 2‾ 1] ATO//[1‾ 2‾ 1] MATO, (1 1 2) ATO//(2 2 0) MAO and [1‾ 2‾ 1] MATO//[1‾ 1 0] for the first time. In addition, the Al2TiO5 porous ceramics with 2 wt% MgCO3 remain phase stable after annealing at 1200 °C for 20 h, and the residual compressive strength is still higher than 88% after 20 cycles of the heating-cooling process at 1400 °C. These results indicate that the Al2TiO5 porous ceramics containing 2 wt% MgCO3 have potential applications in the porous media combustion (PMC) field.

Keywords

• Porous ceramics
• Al2TiO5
• Magnesite
• Crystallographic orientation
• Thermal stability