Continuous sintering of self-reinforced silicon nitride containing reduced amounts of sintering aids

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:175575

Wittmer, D E; Conover, J J; Knapp, V A ^[1]

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1. Southern Illinois Univ., Carbondale, IL (United States); and others

Seeding of Si{sub 3} N{sub 4} to promote the in-situ formation of elongated {beta}-Si{sub 3}N{sub 4}during sintering was investigated for continuously sintered Si{sub 3}N{sub 4} compositions. Si{sub 3}N{sub 4} formulations containing 2 or 4 wt% A1{sub 2}O{sub 3} and 6 or 8 wt% Y{sub 2}O{sub 3}, with and without the addition of 5 wt% {beta}-Si{sub 3}N{sub 4} seed, were continuously sintered for 30 to 90 min in 1 atm of flowing N{sub 2}, over the temperature range of 1700 to 1750{degrees}C. Room temperature four-point flexural strength was slightly lower and fracture toughness was only marginally improved by the addition of {beta}-Si{sub 3}N{sub 4} seed. XRD and microstructural results indicated that the addition of {beta}-Si{sub 3}N{sub 4} seed does promote the in-situ formation of {beta}-Si{sub 3}N{sub 4} at lower sintering times and temperatures.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 175575
• Report Number(s): CONF-9501103--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
CERAMICS
FLEXURAL STRENGTH
FRACTURE PROPERTIES
MICROSTRUCTURE
SILICON NITRIDES
SINTERING
SYNTHESIS
TEMPERATURE DEPENDENCE