Consolidation of Nano-Crystalline Alumina

Abstract
Dense alpha alumina was fabricated from seeded nano-crystalline boehmites. The intrinsic problem of boehmite solubility and hard agglomerate formation was avoided by dispersing gel agglomerates in ethanol. Homogeneous green microstructure and high sintered density were obtained by dry pressing. The superplasticity of nano-crystalline transition alumina was utilized to obtain fully dense, transparent alpha alumina by sinter forging. The effects of seeding and pressure are correlated with the microstructural evolution and densification of alumina.