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Small fatigue crack growth behavior of titanium alloy TC4 at different stress ratios
Author(s) -
Hu XuTeng,
Zhu Lei,
Jiang Rong,
Song YingDong,
Qu ShouDao
Publication year - 2019
Publication title -
fatigue and fracture of engineering materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 84
eISSN - 1460-2695
pISSN - 8756-758X
DOI - 10.1111/ffe.12911
Subject(s) - materials science , crack closure , paris' law , titanium alloy , stress concentration , crack growth resistance curve , stress intensity factor , alloy , tension (geology) , composite material , stress (linguistics) , metallurgy , structural engineering , fracture mechanics , ultimate tensile strength , engineering , linguistics , philosophy
In this paper, the small fatigue crack behavior of titanium alloy TC4 at different stress ratios was investigated. Single‐edge‐notch tension specimens were fatigued axially under a nominal maximum stress of 370 MPa at room temperature. Results indicate that fatigue cracks in TC4 initiate from the interface between α and β phases or within α phase. More than 90% of the total fatigue life is consumed in the small crack initiation and growth stages. The crack growth process of TC4 can be divided into three typical stages, ie, microstructurally small crack stage, physically small crack stage, and long crack stage. Although the stress ratio has a significant effect on the total fatigue life and crack initiation life at constant σ max , its effect on crack growth rate is indistinguishable at R = −0.1, 0.1, and 0.3 when crack growth rate is plotted as a function of ∆ K .