Some Roles of MgO and TiO ₂ in Densification of a Sinterable Alumina

Abstract

Sinterability of undoped, MgO‐doped, and TiO 2 ‐doped Al 2 O 3 has been examined by applying reported sintering equations. The order of sinterability was MgO‐doped ∼ undoped≪ TiO 2 ‐doped Al 2 O 3 in the initial and intermediate stages of sintering, but a relative sintered density at 1600°C for 1 h occurred in the order undoped < TiO 2 ‐doped < MgO‐doped AI 2 O 3 . The dispersion of thermal grooving angles increased in the order MgO‐doped < undoped < TiO 2 ‐doped Al 2 O 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.