Compaction of submicron and nanocrystalline Al sub 2 O sub 3 -ZrO sub 2 ceramics

Conference · Wed Jan 01 04:00:00 EST 1992

OSTI ID:7143639

McKittrick, J; Tunaboylu, B ^[1]; Katz, J ^[2]

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1. California Univ., San Diego, La Jolla, CA (United States)
2. Los Alamos National Lab., NM (United States)

The eutectic in the Al{sub 2}O{sub 3}-ZrO{sub 2} system was rapidly solidified by heating with an 0{sub 2}-H{sub 2} torch and then quenching the melt with a twin roller device. The as-quenched material, which was amorphous or nanocrystalline, was milled with B{sub 4}C or Al{sub 2}0{sub 3} media and pressed into pellets which were sintered conventionally or with microwaves. Samples contaminated with boron carbideresulted in compacts with substantially reduced porosity and a lower fraction of tetragonal ZrO{sub 2}. Conventional sintering at low temperatures resulted in the formation of rods'' of an Al{sub 2}0{sub 3} rich phase which grew from the presence of a low melting B{sub 2}0{sub 3}-rich liquid. Conventional and microwave sintering at temperatures up to 1600{degrees}C resulted in a microstructure where 100--200 nm ZrO{sub 2} grains were present intragranularly in the {alpha}-Al{sub 2}0{sub 3} grains. Larger ZrO{sub 2} grains ({approximately}1 {mu}m) were found intergranularly. As-quenched lamellar microstructures were preserved at low temperatures but spheroidized at sintering temperatures > 1600{degrees}C.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: DOD; Department of Defense, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 7143639
• Report Number(s): LA-UR-92-2721; CONF-9207146--1; ON: DE92040233
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BINARY MIXTURES
BORON CARBIDES
BORON COMPOUNDS
BORON OXIDES
CARBIDES
CARBON COMPOUNDS
CHALCOGENIDES
COHERENT SCATTERING
COMPACTING
CRYSTAL STRUCTURE
DIFFRACTION
DISPERSIONS
ELECTRON MICROSCOPY
EUTECTICS
FABRICATION
MICROSCOPY
MICROSTRUCTURE
MIXTURES
OXIDES
OXYGEN COMPOUNDS
POWDERS
SCANNING ELECTRON MICROSCOPY
SCATTERING
SINTERING
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES