Low-temperature fine-grained alumina-aluminum titanate composites produced from a titania-coated alumina precursor

Abstract

A method for the preparation of alumina-aluminum titanate (AT) composites, which can be sintered to high density with a fine-grained microstructure at < 1450 degrees C, is reported. The composite precursor is alumina particles coated by sol-gel-derived titania, which reacts during sintering to form AT in situ at temperature as low as 1300 degrees C. The composite can be sintered at 1350 degrees C to 98% density with 1.5-2.0 mu m grain size. Other composites containing 5-50 wt% AT are also investigated.