Influence of dispersed β phase on local deformation pattern in mill-annealed Ti-Fe-O alloy under dwell fatigue loading

Abstract

Grain-scale dwell fatigue behavior in Ti-Fe-O alloy is elucidated, with attention focused on the stress redistribution phenomenon that occurs within the soft-hard grain combination. Elastoplastic properties of the beta phase are determined using nanoindentation and crystal plasticity modeling. On this basis, the role of intergranular beta lath on stress redistribution is evaluated. Redistribution of stress from the soft to hard alpha grain is inhibited in the presence of intergranular beta lath during dwell period. Meanwhile, the peak stress in the beta lath is enhanced. This may result in the competition of two dwell fatigue failure modes at high stress state.