Fatigue properties of SiC/Al composites

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:7032077

Gomez, III, J P

Silicon carbide monofilaments, produced by chemical vapor deposition, have several different classifications depending on the surface treatment imparted to the fiber at the final stage of production. The newest of these fibers, designated SCS-8, is produced specifically for aluminum matrix composites in an attempt to improve transverse mechanical properties over the other types. This study focuses on the response of SCS-8/6061 Al alloy composites to cyclic loading. Laminates with fibers oriented in the 0{degree}, 90{degree} and {plus minus}45{degree} direction were used. Particular emphasis was on elastic modulus changes due to fatigue. Unnotched specimens were axially loaded in tension-tension (R = 0.1) mode with a sinusoidal waveform at a frequency of a 10 Hz. Periodically, cycling was stopped and the specimen elastic modulus determined. Fractographic observation indicates several failures modes: fiber splitting, fiber/matrix debonding, matrix shear failure, inter-ply delamination, and fiber fracture. Axial tension-high cycle fatigue behavior is controlled by the matrix. Low-cycle fatigue and static behavior is characterized by progressive failure of the SiC fiber. Modulus change is the result of crack propagation along the fiber-matrix interface.

• Research Organization: Virginia Univ., Charlottesville, VA (USA)
• OSTI ID: 7032077
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ALLOYS
ALUMINIUM ALLOYS
CARBIDES
CARBON COMPOUNDS
CHEMICAL COATING
CHEMICAL VAPOR DEPOSITION
COMPOSITE MATERIALS
DEPOSITION
ELASTICITY
FATIGUE
FIBERS
MATERIALS
MATRIX MATERIALS
MECHANICAL PROPERTIES
SILICON CARBIDES
SILICON COMPOUNDS
SURFACE COATING
TENSILE PROPERTIES