Abstract
Fatigue crack initiation in Ti-6Al-4V has been investigated in high cycle fatigue (HCF) and low cycle fatigue (LCF) regimes at stress ratio R=0.1 using the replication technique. In all four tested α/β microstructures, the crack was initiated by fracture of equiaxed alpha grain. Fractured alpha grains are seen on the fracture surface as flat facets with features characteristics of cleavage fracture. In the regime of low stress amplitudes and in the absence of reverse loading, cleavage fracture contributes to crack initiation and early stages of crack growth in Ti-6Al-4V. This mechanism is discussed in relation to the anomalous mean stress fatigue behavior exhibited by this alloy.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
A.L. Dowson, C.J. Beevers, and L. Grabowski: “The Microstructural Features Associated with the Growth of Short Fatigue Cracks in a Near-Alpha Ti Alloy” in Titanium ’92, Science and Technology, F.H. Froes and I. Caplan, ed., TMS, Warrendale, PA, 1993, pp. 1741–48.
R.J. Wanhill and H. Doker: “Vacuum Fatigue Fracture of Ti-6Al-4V,” in Proceedings of Third International Conference on Titanium, Plenum Press, New York, NY, 1982, pp. 799–810.
P.E. Irving and C.J. Beevers: “Microstructural Influences on Fatigue Crack Growth in Ti-6Al-4V,” Mater. Sci. Eng., 1974, 14, pp. 229–38.
K. Sadananda: “A Dislocation Model for Faceted Mode of Fatigue Crack Growth” in Dislocation Modeling of Physical Systems, M.F. Ashby, R. Bullough, C.S. Hartley, and J.P. Hirth, ed., Pergamon Press, New York, NY, 1981, pp. 69–73.
D.A. Meyn: “Analysis of Frequency and Amplitude Effects on Corrosion Fatigue Crack Propagation in Ti-8Al-1Mo-1V” Metall. Trans., 1971, 2, p. 853.
D.F. Neal and P.A. Blenkinsop: “Internal Fatigue Origins in α-β Titanium Alloys,” Acta Metall., 1976, 24, pp. 59–63.
A.N. Stroh: “Theory of the Fracture of Metals,” Adv. Phys., 1957, 6, p. 418.
A.M. Freudenthal: “New Aspects of Fatigue and Fracture Mechanics,” Eng. Fract. Mech., 1974, 8(6), pp. 775–93.
R.K. Steele and A.J. McEvily: “The High-Cycle Fatigue Behavior of Ti-6Al-4V Alloy,” Eng. Fract. Mech., 1976, 8(1), pp. 31–37.
S. Adachi, L. Wagner, and G. Lütjering: “Influence of Mean Stress on Fatigue Strength of Ti-6Al-4V” in Proceedings 7th International Conference on Strength of Metals and Alloys, H.L. McQueen, J.P. Bailon, and J.I. Dickson, ed., Pergamon Press, New York, NY, 1986, p. 2117.
S. Adachi: Mean Stress Dependence of Fatigue Strength in Titanium Alloys, Ph.D. Thesis, Technischen Universitat Hamburg-Harburg, Germany, 1987.
S.G. Ivanova, F.S. Cohen, R.R. Biederman, and R.D. Sisson Jr.: “Role of Microstructure in the Mean Stress Dependence of Fatigue Strength in Ti-6Al-4V Alloy” in Fatigue Behavior of Titanium Alloys, R.R. Boyer, D. Eylon, and G. Lütjering, ed., TMS, Warrendale, PA, 1999, pp. 39–46.
R.I. Jaffe and G. Lütjering: “Effect of Microstructure and Loading Condition on Fatigue of Ti-6Al-4V Alloy” in Microstructure, Fracture Toughness and Fatigue Crack Growth Rate in Titanium Alloys, A.K. Chakrabarty and J.C. Chesnutt, ed., AIME, Warrendale, PA, 1987, p. 193.
G. Henry: Fractography and Microfractography, Vol. 5, Verlag Stahleisen, Dusseldorf, Germany, p. 445.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Ivanova, S.G., Biederman, R.R. & Sisson, R.D. Investigation of fatigue crack initiation in Ti-6Al-4V during tensile-tensile fatigue. J. of Materi Eng and Perform 11, 226–231 (2002). https://doi.org/10.1361/105994902770344312
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1361/105994902770344312