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Characterization of the Sol-Gel Transition for Zirconia-Toughened Alumina PrecursorsHigh purity ZTA ceramic powders with and without yttria were produced using metal alkoxide precursors. ZTA ceramic powders with varying volume percents of zirconia were prepared (7, 15, and 22%). Aluminum tri-sec butoxide, zirconium propoxide, and yttrium isopropoxide were the reagents used. Synthesis conditions were varied to control the hydrolysis and the aging conditions for the sol to gel transition. FTIR analysis and theological characterization were used to follow the structural evolution during the sol to gel transition. The greater extent of hydrolysis and the build-up of structure measured from viscoelastic properties were consistent. Heat treatment was conducted to produce submicron grain fully crystalline ZTA ceramic powders. In all experimental cases a-alumina and tetragonal zirconia phases were confirmed even in the absence of yttria.
Document ID
20000032219
Acquisition Source
Headquarters
Document Type
Conference Paper
Authors
Moeti, I.
(Clark-Atlanta Univ. GA United States)
Karikari, E.
(Clark-Atlanta Univ. GA United States)
Chen, J.
(Clark-Atlanta Univ. GA United States)
Date Acquired
August 19, 2013
Publication Date
February 22, 1998
Publication Information
Publication: NASA University Research Centers Technical Advances in Aeronautics, Space Sciences and Technology, Earth Systems Sciences, Global Hydrology, and Education
Volume: 2 and 3
Subject Category
Nonmetallic Materials
Funding Number(s)
CONTRACT_GRANT: DAAL03-92-G-0380
CONTRACT_GRANT: NAG4-11
CONTRACT_GRANT: NAGW-2939
CONTRACT_GRANT: EPA-CR-818689
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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