Microstructure and mechanical properties of the in situ [beta]-Si[sub 3]N[sub 4]/[alpha][prime]-SiAlON composite

Journal Article · Thu Sep 01 00:00:00 EDT 1994 · Journal of the American Ceramic Society; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1994.tb04604.x· OSTI ID:6932188

Sheu, T S ^[1]

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1. Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Materials Science and Engineering

The in situ [beta]-Si[sub 3]N[sub 4]/[alpha][prime]-SiAlON composite was studied along the Si[sub 3]N[sub 4]-Y[sub 2]O[sub 3]:9AlN composition line. This two-phase composite was fully densified at 1,780 C by hot pressing. Densification curves and phase developments of the [beta]-Si[sub 3]N[sub 4]/[alpha][prime]-SiAlON composite were found to vary with composition. Because of the cooperative formation of [alpha][prime]-SiAlON and [beta]-Si[sub 3]N[sub 4] during its phase development, this composite had equiaxed [alpha][prime]-SiAlON ([approximately]0.2 [mu]m) and elongated [beta]-Si[sub 3]N[sub 4] fine grains. The optimum mechanical properties of this two-phase composite were in the sample with 30--40% [alpha][prime], which had a flexural strength of 1100 MPa at 25 C, 800 MPa at 1,400 C in air, and a fracture toughness 6 MPa[center dot]m[sup 1/2]. [alpha][prime]-SiAlON grains were equiaxed under a sintering condition at 1,780 C or lower temperatures. Morphologies of the [alpha][prime]-SiAlON grains were affected by the sintering conditions.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6932188
• Journal Information: Journal of the American Ceramic Society; (United States), Journal Name: Journal of the American Ceramic Society; (United States) Vol. 77:9; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
360603 -- Materials-- Properties
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
COMPACTING
COMPOSITE MATERIALS
DATA
EXPERIMENTAL DATA
FRACTURE PROPERTIES
INFORMATION
MATERIALS
MECHANICAL PROPERTIES
MICROSTRUCTURE
NITRIDES
NITROGEN COMPOUNDS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PNICTIDES
SILICON COMPOUNDS
SILICON NITRIDES