Alumina-aluminium titanate composites with improved thermal shock resistance

The influence of small additions of aluminium titanate (5 and 10 vol%) on the thermal shock resistance of alumina is studied. Fine grained (approximate to0.5-2 mum) and dense (greater than or equal to 98 %rho (th)) alumina and composite materials with similar microstructures (porosity and grain size distribution) have been characterised to investigate the effect of aluminium titanate on the thermal shock behaviour. Indented samples have been tested in quenching, and the growth of the symmetric cracks at the corners of the Vickers indentations has been determined. Aluminium. titanate increases the thermal shock resistance (DeltaT(c)) of the alumina matrix up to a 43%. Results agree with the theoretical relations calculated using the properties of the materials.