Densification and microstructure of sodium-doped colloidal mullite

Journal Article · Sun May 01 04:00:00 EDT 1994 · Journal of the American Ceramic Society; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1994.tb05421.x· OSTI ID:7114831

Fahrenholtz, W G; Smith, D M ^[1]

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1. Univ. of New Mexico, Albuquerque, NM (United States). UNM/NSF Center for Micro-Engineering Ceramics

A series of mullite gels was prepared by hetero-coagulation of boehmite and colloidal silica. Samples were doped with up to 1.5 wt% Na[sub 2]O. Na[sub 2]O additions as low as 0.16 wt% led to the formation of [alpha]-alumina and a stable glassy phase in addition to mullite. No evidence for the incorporation of sodium into the mullite structure was found by either XRD or [sup 27]Al MAS NMR. SEM showed mullite doped with 0.16 wt% and greater Na[sub 2]O had an intergranular glassy phase and large crystalline grains. It is thought that the majority of the sodium was present in the glassy phase. Sodium addition did not decrease the mullite crystallization temperature and did not lead to enhanced sintering.

• OSTI ID: 7114831
• Journal Information: Journal of the American Ceramic Society; (United States), Journal Name: Journal of the American Ceramic Society; (United States) Vol. 77:5; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ALKALI METAL COMPOUNDS
ALUMINIUM 27
ALUMINIUM COMPOUNDS
ALUMINIUM ISOTOPES
ALUMINIUM OXIDES
CHALCOGENIDES
CHEMICAL PREPARATION
COHERENT SCATTERING
COMPACTING
DATA
DIFFRACTION
DOPED MATERIALS
ELECTRON MICROSCOPY
EXPERIMENTAL DATA
FABRICATION
INFORMATION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MATERIALS
MICROSCOPY
MICROSTRUCTURE
MINERALS
MULLITE
NUCLEAR MAGNETIC RESONANCE
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
RESONANCE
SCANNING ELECTRON MICROSCOPY
SCATTERING
SINTERING
SODIUM COMPOUNDS
SODIUM OXIDES
STABLE ISOTOPES
SYNTHESIS
X-RAY DIFFRACTION