An investigation of the effects of stress ratio on the micromechanisms of long and short fatigue crack growth in Ti-6Al-4V

Conference · Thu Jul 01 04:00:00 EDT 1999

OSTI ID:20013309

Sinha, V; Mercer, C; Soboyejo, W O

This paper presents the results of a recent study of the effects of positive stress ratios on the propagation of long and short fatigue cracks in mill annealed Ti-6Al-4V. Differences between the long fatigue crack growth rates at positive stress ratios (R = K{sub min}/K{sub max} = 0.02--0.8) are attributed largely to the effects of crack closure. Microstructurally short fatigue cracks are shown to grow at stress intensity factor ranges below the long crack fatigue threshold. Anomalously high fatigue crack growth rates and crack retardation are also shown to occur in the short crack regime until the short crack data merge with the long crack growth rate data in the Paris regime. Differences between the long and the short crack behavior are associated with differences in fatigue crack growth mechanisms.

• Research Organization: Ohio State Univ., Columbus, OH (US)
• Sponsoring Organization: National Science Foundation
• OSTI ID: 20013309
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
CRACK PROPAGATION
EXPERIMENTAL DATA
FATIGUE
STRESS INTENSITY FACTORS
STRESSES
TITANIUM BASE ALLOYS
VANADIUM ALLOYS