Fracture toughness of SiC/Al composites

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:7149715

Flom, Y

Discontinuous SiC/Al composites were fabricated with different size SiC particles in order to study the role of particle size on the fracture process. Tensile-test data show that the Young's modulus in independent of SiC particle size, whereas yield stress and ultimate strength decreases, and strain to fracture and ductility increases as SiC particle size increases. The fracture behavior of SiC/Al is unique in the sense that it has features of brittle and ductile mechanisms. The fracture process is matrix controlled up to SiC particle sizes of 20 ..mu..m and above, where fracture of SiC begins to dominate. The matrix is influenced by residual hydrostatic tension and high density of dislocations generated at SiC/Al interfaces due to the difference in coefficient of thermal expansion (CTE) between SiC and Al matrix. The crack-initiation fracture toughness does not depend on SiC particle size, and the crack-growth fracture toughness increases as the size of the SiC particles increase.

• Research Organization: Maryland Univ., College Park (USA)
• OSTI ID: 7149715
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ALUMINIUM
CARBIDES
CARBON COMPOUNDS
COMPOSITE MATERIALS
CRACKS
ELEMENTS
FRACTURE PROPERTIES
MATERIALS
MECHANICAL PROPERTIES
METALS
PARTICLE SIZE
SILICON CARBIDES
SILICON COMPOUNDS
SIZE
TENSILE PROPERTIES