SOME ROLES OF MGO AND TIO2 IN DENSIFICATION OF A SINTERABLE ALUMINA

Sinterability of undoped, MgO-doped, and TiO//2-doped Al//2O//3 has been examined by applying reported sintering equations. The order of sinterability was MgO-doped approximately equals undoped VM LS TH TiO//2-doped Al//2O//3 in the initial and intermediate stages of sintering, but a relative sintered density at 1600 degree C for 1 h occurred in the order undoped approximately equals TiO//2-doped less than MgO-doped Al//2O//3. The dispersion of thermal grooving angles increased in the order MgO-doped less than undoped less than TiO//2-doped Al//2O//3. The change of sinterability by the dopants is explained in terms of mobility of mass transfer estimated from a densification rate in the initial- and intermediate-stage sintering and of dispersed driving forces of densification and grain growth qualitatively evaluated from the width of the dispersion of thermal grooving angles.