Sintered-reaction Bonded Silicon Nitride Densified by a Gas Pressure Sintering Process Effects of Rare Earth Oxide Sintering Additives

Journal Article · Sun Jan 01 04:00:00 EST 2012 · Journal of the Korean Ceramic Society

DOI:https://doi.org/10.4191/kcers.2012.49.4.318· OSTI ID:1049163

Lee, S. H. ^[1]; Ko, J. W. ^[1]; Park, Y. J. ^[1]; Kim, H. D. ^[1]; Lin, Hua-Tay ^[2]; Becher, Paul F ^[2]

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1. Korea Institute of Materials Science
2. ORNL

Reaction-bonded silicon nitrides containing rare-earth oxide sintering additives were densified by gas pressure sintering. The sintering behavior, microstructure and mechanical properties of the resultant specimens were analyzed. For that purpose, Lu2O3-SiO2 (US), La2O3-MgO (AM) and Y2O3-Al2O3 (YA) additive systems were selected. Among the tested compositions, densification of silicon nitride occurred at the lowest temperature when using the La2O3-MgO system. Since the Lu2O3-SiO2 system has the highest melting temperature, full densification could not be achieved after sintering at 1950oC. However, the system had a reasonably high bending strength of 527 MPa at 1200oC in air and a high fracture toughness of 9.2 MPa m1/2. The Y2O3-Al2O3 system had the highest room temperature bending strength of 1.2 GPa

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: ORNL work for others
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1049163
• Journal Information: Journal of the Korean Ceramic Society, Journal Name: Journal of the Korean Ceramic Society Journal Issue: 4 Vol. 49; ISSN 1229-7801
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ADDITIVES
AIR
BENDING
FRACTURE PROPERTIES
MECHANICAL PROPERTIES
MELTING
MICROSTRUCTURE
OXIDES
RARE EARTHS
SILICON NITRIDES
SINTERING