Fatigue and fracture behavior of Nb fiber-reinforced MoSi{sub 2} composites

Journal Article · Thu Aug 01 04:00:00 EDT 1996 · Metallurgical Transactions, A

OSTI ID:367291

Soboyejo, W O; Ye, F ^[1]; Schwartz, D S ^[2]

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1. Ohio State Univ., Columbus, OH (United States). Dept. of Materials Science and Engineering
2. McDonnell Douglas Aerospace, St. Louis, MO (United States)

Fatigue and fracture mechanisms in Nb fiber-reinforced MoSi{sub 2} composites are elucidated in this article. The effects of fiber diameter on fracture and crack-tip shielding mechanisms are discussed after a review of micromechanical models which are applied to the prediction of residual stress levels, toughening, and microcracking phenomena. Toughening is shown to occur by a combination of crack bridging and crack-tip blunting under monotonic and cyclic loading. Composites with smaller (250-{micro}m) fiber diameters are shown to have better fatigue resistance and lower fracture toughness than composites with larger (750-{micro}m) fiber diameters. The occurrence of slower fatigue crack growth rates in the composites reinforced with smaller diameter Nb fibers is rationalized by assessing the combined effects of fiber spacing and interfacial crack growth on the average crack growth rates within the composites.

• OSTI ID: 367291
• Journal Information: Metallurgical Transactions, A, Journal Name: Metallurgical Transactions, A Journal Issue: 8 Vol. 27; ISSN 0360-2133; ISSN MTTABN
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
36 MATERIALS SCIENCE
AEROSPACE INDUSTRY
COMPOSITE MATERIALS
CRACK PROPAGATION
DUCTILITY
FATIGUE
FRACTURE PROPERTIES
FRACTURES
INTERFACES
INTERMETALLIC COMPOUNDS
MOLYBDENUM SILICIDES
NIOBIUM
RESIDUAL STRESSES