Effect of mean stress (stress ratio) and aging on fatigue-crack growth in a metastable beta titanium alloy, Ti-10V-2Fe-3Al

Journal Article · Wed Mar 01 04:00:00 EST 2000 · Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science

DOI:https://doi.org/10.1007/s11661-000-0012-7· OSTI ID:20023145

Jha, S K; Ravichandran, K S

The effect of mean stress, or the stress ratio (R), on the fatigue-crack growth (FCG) behavior of {alpha}-aged and {omega}-aged microstructures of the beta titanium alloy Ti-10V-2Fe-3Al was investigated. While the mean stress had a negligible effect on the FCG behavior of the {alpha}-aged microstructure, a strong effect was observed in the {omega}-aged microstructure. In particular, the values of the threshold stress-intensity range ({Delta}K{sub th}) exhibited a strong dependence on R in the {omega}-aged microstructure, while this dependence was weak in the {alpha}-aged microstructure. These effects seem to arise primarily from fracture-surface roughness-induced crack closure. The crack closure levels for the {alpha}-aged microstructure were found to be very low compared to those for the {omega}-aged microstructure. Transmission electron microscopy and scanning electron microscopy studies of microstructures and fracture surfaces were performed to gain insight into the deformation characteristics and crack propagation mechanisms, respectively, in these microstructures. The microstructure-induced differences in FCG behavior are rationalized in terms of the effect of aging on slip and crack closure.

• Research Organization: Univ. of Utah, Salt Lake City, UT (US)
• OSTI ID: 20023145
• Journal Information: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, Journal Name: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science Journal Issue: 3 Vol. 31; ISSN MMTAEB; ISSN 1073-5623
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
CRACK PROPAGATION
FATIGUE
FRACTURE MECHANICS
IRON ALLOYS
MICROSTRUCTURE
STRESS INTENSITY FACTORS
STRESSES
TITANIUM ALLOYS
VANADIUM ALLOYS