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Sintering of Mixtures of Seeded Boehmite and Ultrafine α‐Alumina
Author(s) -
Kwon Seongtae,
Messing Gary L.
Publication year - 2000
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2000.tb01152.x
Subject(s) - boehmite , materials science , sintering , shrinkage , microstructure , alumina ceramic , pressing , composite material , chemical engineering , metallurgy , ceramic , aluminium , engineering
α‐Alumina was fabricated by dry pressing mixtures of seeded boehmite and fine α‐alumina (i.e., 0.2 and 0.3 μm diameter) to reduce the large shrinkage of boehmite‐derived α‐alumina. The maximum green density was obtained with mixtures containing ∼70%α‐alumina for both alumina powders. The ∼15% linear shrinkage and microstructures of these samples were comparable to 100% alumina powder samples. Samples with 0.2 μm alumina sintered to densities >95% at 1300°C whereas 1400°C was needed for samples with 0.3 μm alumina. These results indicate that boehmite can be used as a substitute for relatively expensive ultrafine α‐alumina powders.