Microstructural effects on the high-cycle fatigue and fracture behaviors of Ti-6Al-4V alloy. (August 2020)

• Record Type: Journal Article
• Authors: Wu, Zhihong; Kou, Hongchao; Tang, Luyao; Chen, Wei; Han, Xiaoning; Deng, Ying; Tang, Bin; Li, Jinshan
• Is Part Of: Engineering fracture mechanics. Volume 235(2020)
• Publication Date: 2020-08
• Subjects: High cycle fatigue -- Titanium alloys -- Microstructure -- S-N curves -- Fractography; Fracture mechanics -- Periodicals; Rupture, Mécanique de la -- Périodiques; Fracture mechanics; Periodicals; 620.112605
• DOI: 10.1016/j.engfracmech.2020.107129
• Languages: English
• ISSNs: 0013-7944

Abstract

Highlights: The room temperature fatigue strength increases with increasing αp percentage. A moderate αp percentage shows slightly higher fatigue strength value at 400 ℃. Too much or too less αp content increases the scatter of fatigue life. Multi-sites crack-initiation accompanying by fatigue steps occurred at 400 ℃. Abstract: In this work, the samples of Ti-6Al-4V alloy are fatigued at room temperature (RT) and 400 ℃ to reveal the effect of microstructure on high-cycle fatigue behaviors. Results show that the RT fatigue strength monotonically increases with increasing primary α (αp ) percentage, while a moderate αp percentage shows slightly higher fatigue strength value at 400 ℃. Ti-6Al-4V with 45–60% αp exhibit relatively long fatigue life and small scatter in fatigue data. The crack-initiation sites of RT failed specimens show isolated or contiguous αp facets. Fatigue steps associated with the multiple crack-initiation are observed in 400 ℃ failed specimens.