Mechanical properties of beta-silicon nitride whisker/silicon nitride matrix composites

Technical Report · Sun Jan 01 04:00:00 EST 1989

OSTI ID:7073746

Neergaard, L J; Homeny, J

Whisker-reinforced ceramic matrix composites have received a great deal of attention for applications as high temperature structural materials in, for example, advanced heat engines and high temperature energy conversion systems. For these applications, where mechanical reliability is critical, the improvements that can be realized in fracture stress and fracture toughness by the addition of whiskers to polycrystalline ceramics are of great interest. The primary role of the whisker reinforcement is to prevent catastrophic brittle failure by activating mechanisms that dissipate energy during crack propagation. Relevant toughening mechanisms include whisker bridging, whisker pullout, crack deflection, and microcrack formation. Of particular importance for optimizing the mechanical reliability of these composites is the effect of the whisker/matrix interfacial characteristics on these toughening mechanisms.

• Research Organization: Illinois Univ., Urbana, IL (USA)
• OSTI ID: 7073746
• Report Number(s): AD-A-220912/0/XAB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360203* -- Ceramics
Cermets
& Refractories-- Mechanical Properties
BRITTLENESS
CERAMICS
COMPOSITE MATERIALS
CONSTRUCTION INDUSTRY
CRACK PROPAGATION
CRACKS
CRYSTALS
ENGINES
FAILURES
FRACTURE MECHANICS
FRACTURE PROPERTIES
HEAT ENGINES
HIGH TEMPERATURE
INDUSTRY
MATERIALS
MECHANICAL PROPERTIES
MECHANICS
MONOCRYSTALS
NITRIDES
NITROGEN COMPOUNDS
PNICTIDES
POLYCRYSTALS
REINFORCED MATERIALS
RELIABILITY
SILICON COMPOUNDS
SILICON NITRIDES
WHISKERS