Elevated-temperature cyclic crack growth in a SiC-TiB[sub 2] composite

Journal Article · Thu Oct 01 00:00:00 EDT 1992 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(92)90402-Z· OSTI ID:7182353

Yao, D; Shang, J K ^[1]

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1. Illinois Univ., Urbana, IL (United States). Dept. of Materials Science and Engineering

This paper reports that the ability to withstand high temperatures and hostile environments has made SiC attractive for structural uses in chemical processing, power generation and industrial waste heat recovery applications. A major concern, however, has been the structural reliability of the ceramic, especially in a high temperature environment. To address this concern, several studies have been conducted in SiC ceramics with the emphasis on delayed failures and effects of high temperature gaseous environments. The structural reliability of a ceramic can be significantly improved by designing composite microstructures that provide shielding effects on a preexisting crack. A recent example of this is the development of SiC composites reinforced with TiB[sub 2]. Addition of 20 [approx] 30% in volume of TiB[sub 2] particles to SiC increases the fracture toughness by a factor of up to 2. The underlying toughening mechanisms are believed to be crack deflection and stress-induced microcracking at the crack tip As these ceramics will ultimately be used at high temperatures and likely experience thermal and mechanical cycling, concerns have been raised as to the mechanical performance and the effectiveness of the room temperature toughening mechanisms under these severe loading conditions. This brief note reports some of the preliminary results on high temperature fatigue crack growth in a TiB[sub 2] particulate-reinforced SiC matrix composite. Up to the temperature studied, the fracture toughness of the composite does not seem to have changed with temperature, but the material becomes more susceptible to fatigue crack growth at the elevated temperature.

• OSTI ID: 7182353
• Journal Information: Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 27:7; ISSN SCRMEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360203* -- Ceramics
Cermets
& Refractories-- Mechanical Properties
360204 -- Ceramics
Cermets
& Refractories-- Physical Properties
360205 -- Ceramics
Cermets
& Refractories-- Corrosion & Erosion
360602 -- Other Materials-- Structure & Phase Studies
BORIDES
BORON COMPOUNDS
CARBIDES
CARBON COMPOUNDS
CERAMICS
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
COMPOSITE MATERIALS
CORROSION
CORROSION RESISTANCE
CRACK PROPAGATION
CRYSTAL STRUCTURE
FABRICATION
FRACTURE PROPERTIES
HEAT RESISTANT MATERIALS
HEAT TREATMENTS
MATERIALS
MATERIALS WORKING
MECHANICAL PROPERTIES
MICROSTRUCTURE
REINFORCED MATERIALS
RELIABILITY
SILICON CARBIDES
SILICON COMPOUNDS
STRESS CORROSION
STRESSES
THERMAL CYCLING
THERMAL STRESSES
THERMOMECHANICAL TREATMENTS
TITANIUM BORIDES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS