Crystal plasicity FE study of the role of microtexture on Dwell Fatigue Response of Ti-6242

Abstract eng:
The fatigue performance of the aero-space alloy Ti-6242 is strongly dependent on its microstructural design. In particular, micro- textured regions (MTRs) are known to be critical features for dwell crack formation. In this work, a Crystal Plasticity FE model and an experimentally validated dwell crack nucleation model of Ti-6242 are used to study the effect of MTRs on dwell fatigue performance of Ti- 6242. A wavelet-based multi-time-scale integration method is used in calculating the material response over fatigue cycles. It is shown that the presence of MTRs results in increased accumulation of local plastic strain, higher stress concentration grain boundaries, and early dwell crack nucleation. Microstructures without MTRs show significantly better fatigue performance. The level of microtexture is characterized by statistical measures which are used as microstructural parameters for structural-scale homogenized models of fatigue damage. Micro- mechanical modeling of fatigue along with homogenization may help understand and predict the structural-scale response in relation to the microstructural-level material design.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket