TY - JOUR
T1 - Influence of notch root radius on high cycle fatigue properties and fatigue crack initiation behavior of Ti-55531 alloy with a multilevel lamellar microstructure
AU - Zhang, Zhong
AU - Huang, Chaowen
AU - Xu, Zilu
AU - Yang, Jiang
AU - Long, Shaolei
AU - Tan, Changsheng
AU - Wan, Mingpan
AU - Liu, Dan
AU - Ji, Shengli
AU - Zeng, Weidong
N1 - Publisher Copyright:
© 2023 The Author(s)
PY - 2023/5/1
Y1 - 2023/5/1
N2 - Notch high cycle fatigue (HCF) properties and microcrack initiation behavior of Ti-55531 alloy with a multilevel lamellar microstructure under various notch radii were systematically investigated. Results indicate that the reduction of notch root radius significantly promotes fatigue microcrack initiation, and then dramatically reduces the HCF life and strength of the alloy. Cyclic deformation of the alloy is mainly controlled by the slipping and deformation twinning in α plates. The primary fatigue crack initiation micro-mechanism is α/β interface cracking induced by slipping and twinning at all notch HCF specimens. Moreover, the volume fraction of twinning would increase with decreasing of the notch root radius. Interestingly, when the notch root radius is the smallest (R = 0.14 mm) and the stress concentration factor is the largest (Kt = 4), in addition to slipping and twinning, basal stacking faults promoting the cracking of α/β interface could be another crucial HCF microcrack initiation mechanism of the alloy. Furthermore, with decreasing of notch root radius and increasing of stress concentration factor, the size of cycle plastic deformation zone at notch root gradually reduces to the size of α colony and even the α plate. Therefore, the order of influential degree of three different levels microstructure on the crack initiation mechanism of notched HCF can be arranged as α plate > α colony > β GB.
AB - Notch high cycle fatigue (HCF) properties and microcrack initiation behavior of Ti-55531 alloy with a multilevel lamellar microstructure under various notch radii were systematically investigated. Results indicate that the reduction of notch root radius significantly promotes fatigue microcrack initiation, and then dramatically reduces the HCF life and strength of the alloy. Cyclic deformation of the alloy is mainly controlled by the slipping and deformation twinning in α plates. The primary fatigue crack initiation micro-mechanism is α/β interface cracking induced by slipping and twinning at all notch HCF specimens. Moreover, the volume fraction of twinning would increase with decreasing of the notch root radius. Interestingly, when the notch root radius is the smallest (R = 0.14 mm) and the stress concentration factor is the largest (Kt = 4), in addition to slipping and twinning, basal stacking faults promoting the cracking of α/β interface could be another crucial HCF microcrack initiation mechanism of the alloy. Furthermore, with decreasing of notch root radius and increasing of stress concentration factor, the size of cycle plastic deformation zone at notch root gradually reduces to the size of α colony and even the α plate. Therefore, the order of influential degree of three different levels microstructure on the crack initiation mechanism of notched HCF can be arranged as α plate > α colony > β GB.
KW - Fatigue crack initiation
KW - Multilevel lamellar microstructure
KW - Notch high cycle fatigue
KW - Ti-55531 alloy
UR - http://www.scopus.com/inward/record.url?scp=85156164214&partnerID=8YFLogxK
U2 - 10.1016/j.jmrt.2023.04.211
DO - 10.1016/j.jmrt.2023.04.211
M3 - 文章
AN - SCOPUS:85156164214
SN - 2238-7854
VL - 24
SP - 6293
EP - 6311
JO - Journal of Materials Research and Technology
JF - Journal of Materials Research and Technology
ER -