Ceramic powders of aluminum titanate (Al2TiO5)-mullite composites with submicrometre sizes were synthesized by the stepwise alkoxide hydrolysis of tetraethylorthosilicate, Si(OC2H5)4 and titanium tetraethoxide, Ti(OC2H5)4, in an Al2O3 ethanol colloidal suspension. All particles produced by the sol-gel process were amorphous and mono-dispersed ones with a narrow size distributions. The reaction of α-Al2O3 with amorphous-TiO2 and -SiO2 to form aluminum titanate and mullite starts in the temperature range of 1280-1300oC and 1450-1480oC, respectively. Al2TiO5-mullite composites sintered at 1600oC showed a moderately high mechanical strength and a low thermal expansion coefficient obtained by inhibiting grain growth of the Al2TiO5 by the addition of mullite.

Keywords: Aluminum titanate, Mullite, Synthesis, Sol-Gel, Formation