Sintering behavior and properties of Si sub 3 N sub 4 sintered with nitrogen-rich liquid in the system Y sub 2 O sub 3 -AlN-SiO sub 2

Journal Article · Sun May 01 04:00:00 EDT 1988 · Advanced Ceramic Materials; (USA)

DOI:https://doi.org/10.1111/j.1551-2916.1988.tb00209.x· OSTI ID:5998316

Das, P K; Mukerji, J ^[1]

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1. Central Glass and Ceramic Research Institute, Calcutta (India)

Pressureless sintering of Si{sub 3}N{sub 4} with selected liquid compositions from the system Y{sub 2}O{sub 3}-AlN-SiO{sub 2} has been reported. Compositions were selected so that the grain-boundary liquid produced YAG(3Y{sub 2}O{sub 3}{center dot}5Al{sub 2}O{sub 3}) after crystallization. Studies on dynamic sintering indicated that the first liquid formation occurred between 1,278 and 1,305{degree}C and the maximum sintering rate was observed between 1,590{degree} and 1,610{degree}C depending on the compositions. Si{sub 2}N{sub 2}O, YAG, or YAG along with YSiO{sub 2}N were the crystalline phases obtained on devitrification as the composition moved toward the AlN corner. The grain boundary liquid phase could be reduced from 20 to 9% on crystallization. Highest flexural strength and fracture toughness obtained were 475 MPa (four-point 45 to 20 mm span) and 6.8 MPa {center dot} m{sup 1/2}, respectively. The effect of crystallization on high-temperature strength and toughness was beneficial in all cases. The creep rate of the sintered product varied from 10.0 {times} 10{sup {minus}7} to 4 {times} 10{sup {minus}5} h{sup {minus}1} between 1,200{degree} and 1,450{degree}C and at 200 to 350 MPa stresses.

• OSTI ID: 5998316
• Journal Information: Advanced Ceramic Materials; (USA), Journal Name: Advanced Ceramic Materials; (USA) Vol. 3:3; ISSN 0883-5551; ISSN ACEME
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ALUMINIUM COMPOUNDS
ALUMINIUM NITRIDES
CHALCOGENIDES
CRYSTAL STRUCTURE
DATA
EXPERIMENTAL DATA
FABRICATION
FLEXURAL STRENGTH
FRACTURE PROPERTIES
GRAIN BOUNDARIES
INFORMATION
MECHANICAL PROPERTIES
MICROSTRUCTURE
NITRIDES
NITROGEN COMPOUNDS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PNICTIDES
SILICON COMPOUNDS
SILICON NITRIDES
SILICON OXIDES
SINTERING
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES