抄録
The effect of the specific surface area of added ρ-alumina on hardening of α-alumina slurry was investigated by the measurement of the penetration resistance of α-alumina slurry. ρ-alumina was made by the heating of Al(OH)3 from 200 to 700°C in vacuum. The penetration resistance increased with increasing holding time. The holding time required to reach the same penetration resistance decreased with increasing specific surface area of ρ-alumina, when it contained neither Al(OH)3 nor η-alumina. In the case where Al(OH)3 remained in ρ-alumina (heat treated below 300°C), the hardening of the slurry proceeded more rapidly than that of the slurry without Al(OH)3, exhibiting about the same specific surface area. When η-alumina was formed (heat treated above 600°C), then the hardening of the slurry proceeded more slowly than that of the slurry without η-alumina.
