Aluminum nitride-silicon carbide whisker composites: Processing, properties, and microstructural stability

Technical Report · Mon Jan 01 00:00:00 EST 1990

DOI:https://doi.org/10.2172/6381576· OSTI ID:6381576

Cross, M T

Aluminum nitride -- silicon carbide whisker composites with up to 20 vol % whiskers were fabricated by pressureless sintering (1750{degree}--1800{degree}C) and by hot-pressing (1700{degree}--1800{degree}C). Silicon carbide whiskers were found to degrade depending on the type of protective powder bed used during sintering. Whiskers were found to degraded in high oxygen containing samples by reaction with sintering additives. Whisker degradation was also due to the formation of silicon carbide -- aluminum nitride solid solution. No whisker degradation was observed in hot-pressed samples. For these samples Young's modulus and fracture toughness were measured. A 33% increase in the fracture toughness was measured by the indentation technique for a 20 vol % whisker composite. Operative toughening mechanisms were investigated using scanning electron microscopy. Crack deflection and whisker bridging were the dominant mechanisms. It was also shown that load transfer from matrix to whiskers can be a contributing factor to toughening. 88 refs., 34 figs., 11 tabs.

• Research Organization: Illinois Univ., Urbana, IL (USA). Graduate Coll.
• Sponsoring Organization: DOE/ER
• DOE Contract Number: AC02-76ER01198
• OSTI ID: 6381576
• Report Number(s): DOE/ER/01198-T43; ON: DE91001907
• Resource Relation: Other Information: Thesis (M.S.)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM NITRIDES
FRACTURE PROPERTIES
SILICON CARBIDES
COMPOSITE MATERIALS
HOT PRESSING
MECHANICAL PROPERTIES
MICROSTRUCTURE
SINTERING
STABILITY
WHISKERS
ALUMINIUM COMPOUNDS
CARBIDES
CARBON COMPOUNDS
CRYSTAL STRUCTURE
CRYSTALS
FABRICATION
MATERIALS
MATERIALS WORKING
MONOCRYSTALS
NITRIDES
NITROGEN COMPOUNDS
PNICTIDES
PRESSING
SILICON COMPOUNDS
360203* - Ceramics
Cermets
& Refractories- Mechanical Properties
360202 - Ceramics
Cermets
& Refractories- Structure & Phase Studies
360603 - Materials- Properties