High-temperature failure mechanisms of hot pressed Si[sub 3]N[sub 4] and Si[sub 3]N[sub 4]/Si[sub 3]N[sub 4]-whisker-reinforced composites

Journal Article · Sat May 01 04:00:00 EDT 1993 · Journal of the American Ceramic Society; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1993.tb03764.x· OSTI ID:6346243

Chu, Chayang; Singh, J P; Routbort, J L ^[1]

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1. Argonne National Lab., IL (United States)

The high-temperature flexural strength of hot-pressed silicon nitride (Si[sub 3]N[sub 4]) and Si[sub 3]N[sub 4]-whisker-reinforced Si[sub 3]N[sub 4]-matrix composites has been measured at a crosshead speed of 1.27 mm/min and temperatures up to 1,400 C in a nitrogen atmosphere. Load-displacement curves for whisker-reinforced composites showed nonelastic fracture behavior at 1,400 C. In contrast, such behavior was not observed for monolithic Si[sub 3]N[sub 4]. Microstructures of both materials have been examined by scanning and transmission electron microscopy. The results indicate that grain-boundary sliding could be responsible for strength degradation in both monolithic Si[sub 3]N[sub 4] and its whisker composites. The origin of the nonelastic failure behavior of Si[sub 3]N[sub 4]-whisker composite at 1,400 C was not positively identified but several possibilities are discussed.

• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6346243
• Journal Information: Journal of the American Ceramic Society; (United States), Journal Name: Journal of the American Ceramic Society; (United States) Vol. 76:5; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360203* -- Ceramics
Cermets
& Refractories-- Mechanical Properties
360602 -- Other Materials-- Structure & Phase Studies
360603 -- Materials-- Properties
COMPOSITE MATERIALS
CRYSTAL STRUCTURE
CRYSTALS
DATA
ELECTRON MICROSCOPY
EXPERIMENTAL DATA
FABRICATION
FAILURES
FLEXURAL STRENGTH
FRACTURE PROPERTIES
GRAIN BOUNDARIES
HOT PRESSING
INFORMATION
MATERIALS
MATERIALS WORKING
MECHANICAL PROPERTIES
MICROSCOPY
MICROSTRUCTURE
MONOCRYSTALS
NITRIDES
NITROGEN COMPOUNDS
NUMERICAL DATA
PNICTIDES
PRESSING
REINFORCED MATERIALS
SILICON COMPOUNDS
SILICON NITRIDES
TEMPERATURE RANGE
TEMPERATURE RANGE 1000-4000 K
WHISKERS