An investigation of fatigue crack growth in a cast lamellar Ti-48Al-2Cr-2Nb alloy

Authors
Mercer, C Lou, J Soboyejo, WO
Citation
C. Mercer et al., An investigation of fatigue crack growth in a cast lamellar Ti-48Al-2Cr-2Nb alloy, MAT SCI E A, 284(1-2), 2000, pp. 235-245
Citations number
21
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
ISSN journal
09215093 → ACNP
Volume
284
Issue
1-2
Year of publication
2000
Pages
235 - 245
Database
ISI
SICI code
0921-5093(20000531)284:1-2<235:AIOFCG>2.0.ZU;2-R
Abstract
The results of a study of fatigue crack growth in a lamellar gamma titanium aluminide alloy are presented in this paper. Differences ill the fatigue c rack growth behavior at 25, 450 and 700 degrees C are shown to be associate d with the combined effects of different fracture modes/crack-tip deformati on mechanisms and oxide-induced crack closure under cyclic loading. Crack-t ip deformation was found to occur by conventional slip at 25 degrees C. At 450 and 700 degrees C, however, crack-tip deformation occurs via a duplex m ode of slip and micro-twinning within lamellae. A higher fatigue threshold at 700 degrees C is attributed partly to the effects of oxide-induced crack closure. (C) 2000 Elsevier Science S.A. All rights reserved.