Reducing the density deviation in alumina by pressure-vacuum hybrid slip casting by employing powders with different particle sizes

Autor: Hai-Doo Kim, Hyun-Kwuon Lee, Jae-Hong Min, Kyeong-Sik Cho
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Journal of Asian Ceramic Societies, Vol 8, Iss 2, Pp 407-415 (2020)
ISSN: 2187-0764
Popis: We reduced the density variation in Al2O3 fabricated by pressure-vacuum hybrid slip casting (PVHSC) by adding small powders to large particles. In PVHSC, consolidation occurs not only by compression of the slip in the casting chamber but also by suction of the dispersion medium from the chamber. Three powders with particles of different sizes [the host powder (H), octahedral-void-filling powder (O), and tetrahedral-void-filling powder (T)] were prepared by milling commercial Al2O3 powders to control the particle size. Slips were prepared using three powder batches: H powder only, a mixture of H and O powders, or a mixture of all three powders. The solid cast green body fabricated from the powder batches including fine powder showed longer constant drying rate periods and drying completion times compared to a batch of the host powder. The green density of Al2O3 made from the mixture of all three powders was 59.4 ± 0.3%, and the density distribution was uniform along the thickness direction. After sintering at 1650°C, the Al2O3 bodies also exhibited the uniform density distribution and higher densities when the powder including fine powder were used.
Databáze: OpenAIRE