High-pressure sintering of nanocrystalline {gamma}-Al{sub 2}O{sub 3}

Journal Article · Fri Nov 01 00:00:00 EST 1996 · Journal of the American Ceramic Society

DOI:https://doi.org/10.1111/j.1151-2916.1996.tb08741.x· OSTI ID:417791

Mishra, R S; Lesher, C E; Mukherjee, A K ^[1]

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1. Univ. of California, Davis, CA (United States)

High-pressure sintering of nanocrystalline {gamma}-Al{sub 2}O{sub 3} has been studied over a temperature range of 923--1,323 K and at a pressure of 1 GPa. The {gamma}-Al{sub 2}O{sub 3} to {alpha}-Al{sub 2}O{sub 3} transformation temperature changed from 1,473 K without pressure to {approximately}1,023 K at 1 GPa. Full density was obtained at 1,273 and 1,323 K in 10 min. The microhardness value of fully dense {alpha}-alumina with a grain size of 142 nm was found to be 25.3 {+-} 0.8 GPa. The Hall-Petch slope for the very fine grain size range is different from that of the coarse-grained alumina.

• Sponsoring Organization: National Science Foundation, Washington, DC (United States); USDOE, Washington, DC (United States)
• DOE Contract Number: FG03-92ER14240
• OSTI ID: 417791
• Journal Information: Journal of the American Ceramic Society, Vol. 79, Issue 11; Other Information: PBD: Nov 1996
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
SINTERING
POWDERS
TEMPERATURE DEPENDENCE
PRESSURE DEPENDENCE
BULK DENSITY
GRAIN SIZE
X-RAY DIFFRACTION
CRYSTAL-PHASE TRANSFORMATIONS
SCANNING ELECTRON MICROSCOPY
MICROHARDNESS
EXPERIMENTAL DATA