Structure and Grain Coarsening During the Sintering of Alumina

Abstract

The pore surface area (Sp) and grain‐boundary area (Sgb) were measured during the sintering of undoped and doped (100 ppm MgO) alumina compacts. Since the presence of the additive affects only Sgb (raising it at a given value of the density), pinning of the boundaries by solid‐solution drag is the only additive function evidenced by the results. The importance of such pinning even at densities as low as 75% of theoretical is linked to the existence of microstructural inhomogeneities.