Colloidal Shaping of Alumina Ceramics by Thermally Induced Gelation of Methylcellulose

Abstract

Dense alumina ceramics have been fabricated by the colloidal shaping of alumina slurry using methylcellulose as the networking additive. Concentration as low as 0.08 wt% of methylcellulose had been found to be sufficient enough to convert an alumina slurry of 74–75 wt% solid loading, to consolidated shapes by thermal gelation at 70°–80°C. Cast shapes could be sintered to dense alumina (99% TD) at temperatures in the range of 1500°–1525°C at a minimum heating rate of 180°C/h. The effect of methylcellulose concentration on the viscosity of suspensions was studied and green strengths of samples are investigated.