Fracture behavior of CVD SiC-coated graphite; 2: Conditions for the onset of multiple cracking

Journal Article · Tue Mar 01 04:00:00 EST 1994 · Journal of the American Ceramic Society; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1994.tb05355.x· OSTI ID:7046345

Watkins, T R; Green, D J ^[1]

---

1. Pennsylvania State Univ., University Park, PA (United States). Dept. of Materials Science and Engineering

Crack arrest and multiple cracking can be observed during the fracture of coated substrates even in the absence of coating delamination. Clearly, it would be useful to understand the mechanics and material parameters that control this process. The conditions for the arrest of the initial crack were modeled using an approximate stress intensity factor approach, and it was determined there is a critical coating thickness, below which the multiple cracking occurs. The critical thickness was determined to depend on the coating strength, substrate toughness, and the relative Young's moduli of the coating and the substrate. The effects of these parameters and residual stresses on the fracture behavior are discussed. The results of the model are compared to the experimental data on a SiC-coated graphite (sandwich composite).

• DOE Contract Number: FG02-86ER45252
• OSTI ID: 7046345
• Journal Information: Journal of the American Ceramic Society; (United States), Journal Name: Journal of the American Ceramic Society; (United States) Vol. 77:3; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
CARBIDES
CARBON
CARBON COMPOUNDS
COMPOSITE MATERIALS
CRACK PROPAGATION
ELEMENTAL MINERALS
ELEMENTS
FRACTURE PROPERTIES
GRAPHITE
MATERIALS
MATHEMATICAL MODELS
MECHANICAL PROPERTIES
MINERALS
NONMETALS
SILICON CARBIDES
SILICON COMPOUNDS