Influence of dispersed β phase on local deformation pattern in mill-annealed Ti-Fe-O alloy under dwell fatigue loading. (November 2021)

• Record Type: Journal Article
• Authors: Yin, Liangwei; Umezawa, Osamu
• Is Part Of: International journal of fatigue. Volume 152(2021)
• Publication Date: 2021-11
• Subjects: Titanium alloy -- Dwell fatigue -- Nanoindentation -- Crystal plasticity -- Slip transfer; Materials -- Fatigue -- Periodicals; Materials -- Fatigue; Periodicals; 620.1122
• DOI: 10.1016/j.ijfatigue.2021.106447
• Languages: English
• ISSNs: 0142-1123

Abstract

Highlights: Load-displacement curves of β single crystal show reasonable agreement between nanoindentation tests and dislocation mechanism-based crystal plasticity modeling. Intergranular β lath within the rogue grain combination reduces the dwell fatigue sensitivity of titanium alloys with globular structure. Geometrical compatibility of the α / β interface significantly affects the stress redistribution phenomenon. Increased peak stress in the intergranular β lath may cause competing dwell fatigue failure modes at the high stress state. 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 β phase are determined using nanoindentation and crystal plasticity modeling. On this basis, the role of intergranular β lath on stress redistribution is evaluated. Redistribution of stress from the soft to hard α grain is inhibited in the presence of intergranular β lath during dwell period. Meanwhile, the peak stress in the β lath is enhanced. This may result in the competition of two dwell fatigue failure modes at high stress state.