Microstructural Characterization and Thermal Properties of Aluminium Titanate/Spinel Ceramic Matrix Composites

Abstract

Spinel (MgAl2O4) ceramics possesses a high melting point, high hardness, a relatively low density, excellent transmittance, a high strength, a relatively low thermal expansion coefficient, high thermal shock resistance and high chemical inertness. Aluminium titanate (Al2TiO5) exhibits extremely good thermal shock resistance and low thermal conductivity coupled with good chemical resistance in molten metals. In the present work, aluminium titanate/spinel ceramics composites with different percentages of Al2TiO5 were prepared using powder metallurgy techniques. The microstructural, mechanical and thermal properties were characterized using X-ray diffraction, scanning electron microscopy, differential scanning calorimetry, dilatometer and hardness. Thermal shock resistance behaviour under water quenching of the as-prepared ceramics was also evaluated. Results revealed that the addition of aluminium titanate to spinel matrix improves the properties of the aluminium titanate/spinel ceramics.