Development of nano-composite microstructures in ZrO{sub 2}-Al{sub 2}O{sub 3} via the solution precursor method

Journal Article · Thu Jun 01 00:00:00 EDT 1995 · Journal of the American Ceramic Society

DOI:https://doi.org/10.1111/j.1151-2916.1995.tb08842.x· OSTI ID:82619

Balmer, M L; Lange, F F; Jayaram, V; Levi, C G ^[1]

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1. Univ. of California, Santa Barbara, CA (United States). Materials Dept.

Aqueous mixtures of zirconium acetate and aluminum nitrate were pyrolyzed and crystallized to form a metastable solid solution, Zr{sub 1{minus}x}Al{sub x}O{sub 2{minus}x/2} (x {le} 0.57). The initial, metastable phase partitions at higher temperatures to form two metastable phases, viz., t-ZrO{sub 2} + {gamma}-Al{sub 2}O{sub 3} with a nano-scale microstructure. The microstructural observations associated with the {gamma}- {yields} {alpha}-Al{sub 2}O{sub 3} phase transformation in the t-ZrO{sub 2} matrix are reported for compositions containing 10, 20, and 40 mol% Al{sub 2}O{sub 3}. During this phase transformation, the {alpha}-Al{sub 2}O{sub 3} grains take the form of a colony of irregular, platelike grains, all with a common crystallographic orientation. The plates contain ZrO{sub 2} inclusions and are separated by ZrO{sub 2} grains. The volume fraction of Al{sub 2}O{sub 3} and the heat treatment conditions influence the final microstructure. At lower volume fractions of Al{sub 2}O{sub 3}, the colonies coarsen to single, irregular plates, surrounded by polycrystalline ZrO{sub 2}. Interpenetrating microstructures produced at high volume fractions of Al{sub 2}O{sub 3}, exhibit very little grain growth for periods up to 24 h at 1,400 C.

• Sponsoring Organization: USDOE
• OSTI ID: 82619
• Journal Information: Journal of the American Ceramic Society, Journal Name: Journal of the American Ceramic Society Journal Issue: 6 Vol. 78; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACETATES
ALUMINIUM NITRATES
ALUMINIUM OXIDES
AQUEOUS SOLUTIONS
COMPOSITE MATERIALS
CRYSTAL-PHASE TRANSFORMATIONS
ELECTRON DIFFRACTION
HEAT TREATMENTS
MICROSTRUCTURE
SCANNING ELECTRON MICROSCOPY
SOLID SOLUTIONS
SYNTHESIS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES