Effect of Phase Transformation and Fine Particle Dispersion on Densification of High Purity Nanocrystalline γ-Phase Dispersed α-Alumina
The effect of phase transformation and fine particle dispersion on densification behavior of high purity nanocrystalline alumina was investigated. The γ/α phase ratio of the mixture compacts were affected detrimentally by sinterability and phase transformation of α-phase alumina ceramics. The densification was significantly deteriorated with increasing γ-phase owing to faceted pores which are caused by the formation of a colony. The faceted pores were not existed in the α- Al2O3 ceramics with 10% γ-phase. Densification of the 10% γ-phase dispersed α-Al2O3 ceramics was significantly enhanced by rapid transformation of α-alumina. The grain growth was effectively inhibited by a small amount of nanoparticle dispersion for the alumina ceramics. As a result, dense nanostructured alumina can be achieved in the 10% γ-phase dispersed α-Al2O3 ceramics, even sintering at 1400oC for 3 hours.
Byung Tae Ahn, Hyeongtag Jeon, Bo Young Hur, Kibae Kim and Jong Wan Park
S. W. Kim and S. Y. Kim, "Effect of Phase Transformation and Fine Particle Dispersion on Densification of High Purity Nanocrystalline γ-Phase Dispersed α-Alumina", Solid State Phenomena, Vols. 124-126, pp. 831-834, 2007