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Enhanced Densification of Boehrmte Sol‐Gels by α‐Alumina Seeding
Author(s) -
Kumagai Masato,
Messing Gary L.
Publication year - 1984
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.1151-2916.1984.tb19491.x
Subject(s) - boehmite , seeding , materials science , chemical engineering , sol gel , nucleation , hydrosol , sintering , composite material , mineralogy , chemistry , nanotechnology , aluminium , organic chemistry , engineering , aerospace engineering
Boehmite sol‐gels were seeded by adding <2.0 wt%α‐alumina powder to a 20% boehmite hydrosol at pH =3. The seeded gel sintered to 98% of theoretical density after 100 min at 1200°C, whereas the unseeded gel had to be sintered at 1600°C to reach 94% of theoretical density. This difference results primarily from nucleation by the α‐alumina seeds and enhanced transformation of the boehmite to α‐alumina, such that a uniform, well‐ordered, fine‐grained α‐alumina micro‐structure forms prior to densification.