Pressureless sintering of dense Si{sub 3}N{sub 4} and Si{sub 3}N{sub 4}/SiC composites with nitrate additives
- Tokyo Inst. of Tech. (Japan)
The effect of aluminum and yttrium nitrate additives on the densification of monolithic Si{sub 3}N{sub 4} and a Si{sub 3}N{sub 4}/SiC composite by pressureless sintering was compared with that of oxide additives. The surfaces of Si{sub 3}N{sub 4} particles milled with aluminum and yttrium nitrates, which were added as methanol solutions, were coated with a different layer containing Al and Y from that of Si{sub 3}N{sub 4} particles milled with oxide additives. Monolithic Si{sub 3}N{sub 4} could be sintered to 94% of theoretical density (TD) at 1,500 C with nitrate additives. The sintering temperature was about 100 C lower than the case with oxide additives. After pressureless sintering at 1,750 C for 2 h in N{sub 2}, the bulk density of a Si{sub 3}N{sub 4}/20 wt% SiC composite reached 95% TD with nitrate additives.
- OSTI ID:
- 413325
- Journal Information:
- Journal of the American Ceramic Society, Journal Name: Journal of the American Ceramic Society Journal Issue: 10 Vol. 79; ISSN 0002-7820; ISSN JACTAW
- Country of Publication:
- United States
- Language:
- English
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