Open AccessJournal Article
An investigation of the effects of microstructure on the fatigue and fracture behavior of α2+β forged Ti-24Al-11Nb
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In this paper, the effects of Widmanstätten and basket weave microstructures on the fracture toughness and fatigue crack growth behavior of Ti-24Al-11 Nb are reported.Abstract:
The results of a recent study of the effects of Widmanstätten and basket weave microstructures on the fracture toughness and fatigue crack growth behavior of Ti-24Al-11 Nb are reported Intrinsic and extrinsic toughening components due to crack blunting and bridging by the β phase, crack deflection, and microcracking are computed from existing crack-tip shielding models. Predictions of fracture toughness and fatigue thresholds obtained by the superposition of extrinsic toughening components are compared with measured values obtained from compression precraked single edge notch (SEN) bend specimens. The results indicate that the continuity of the β matrix between the α2 laths is important for the effectiveness of crack-tip blunting mechanisms. Widmanstätten microstructures obtained by annealing solely in the α2 + β phase field are shown to promote crack deflection and unstable room-temperature fatigue crack growth rates.i.e., crack growth rates that increase after further thermal exposure in the α2 + β and field. Basket weave microstructures produced by two-stage annealing (TSA) in the β and α2 + β phase fields are shown to promote crack bifurcation and deflection and significant improvements in fatigue crack growth resistance when the β anneal is followed by a furnacecool. The article highlights the significant role of microcracking in the fatigue propagation mechanism. The micromechanisms of fatigue and fracture are also discussed for the microstructures examined.read more
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Toughening mechanisms in titanium aluminides
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An Investigation of Fatigue Crack Nucleation and Growth in a Ti–6Al–4V/TiB in Situ Composite
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Effects of reinforcement morphology on the fatigue and fracture behavior of MoSi2/Nb composites
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Microstructure evolution and its effect on tensile and fracture behaviour of Ti-AI-Nb α2 intermetallics
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Fusion zone microstructure and fatigue crack growth behaviour in Ti-6Al-4V alloy weldments
TL;DR: In this paper, the fatigue crack growth resistance of α-β titanium alloys can be altered by microstructural modification during welding, the fusion zone microstructure depends on cooling rate.
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Brian Cotterell,James R. Rice +1 more
TL;DR: In this paper, a solution for the elastic stress intensity factors at the tip of a slightly curved or kinked two-dimensional crack is presented for the deviation of the crack surface from a straight line and is carried out by perturbation procedures analogous to those of Banichuk [1] and Goldstein and Salganik [2, 3].
Journal ArticleDOI
Limitations to the small scale yielding approximation for crack tip plasticity
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Journal ArticleDOI
A new ordered orthorhombic phase in a Ti3AlNb alloy
TL;DR: An ordered orthorhombic phase has been detected in a Ti-25at.% Al-12.5at. alloy as discussed by the authors, which is one of a family of Ti3Al base alloys under development for high temperature applications.
Journal ArticleDOI
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TL;DR: In this article, an examination of the fracture surfaces of ductile metal specimens broken in high stress fatigue has revealed the occurrence of fracture ripples similar in appearance to those resulting from low stresses, but considerably larger.
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