TY - JOUR
T1 - 高强韧Ti-3Al-5Mo-4Cr-2Zr-1Fe合金低周疲劳性能研究
AU - Zhang, Hang
AU - Sun, Yangyang
AU - Alexandrov, Igor V.
AU - Fang, Zhigang
AU - Yi, Chengjie
AU - Dong, Yuecheng
AU - Chang, Hui
AU - Zhou, Lian
N1 - Publisher Copyright:
© 2021, Science Press. All right reserved.
PY - 2021/2
Y1 - 2021/2
N2 - Low cycle fatigue (LCF) behavior of Ti-3Al-5Mo-4Cr-2Zr-1Fe (Ti-35421) alloy with bimodal microstructure consisting of lath α(αp) and βtrans was investigated by strain-controlled mode at room temperature. Results indicate that cyclic stress amplitudes of the Ti-35421 alloy with bimodal microstructure show cyclic softening at first, then reach to cyclic stability at high strain amplitude (Δεt/2=1.0%, 1.2%, 1.4%, 1.6%). However, the cyclic stress response characterizes cyclic saturation at low strain amplitudes (Δεt/2=0.6%, 0.8%). Only one fatigue crack source is found by fracture morphology observation when Δεt/2=0.6%, while a large number of small secondary cracks occur on the surface. On the contrary, multiple fatigue crack sources generate when the strain amplitude increases to 1.6%. The number of secondary cracks reduces, but the length and width of the secondary cracks increase significantly. TEM results indicate that a large number of dislocations generate at the αp/βtrans interface at the low strain amplitude (Δεt/2=0.6%), which leads to micro-crack nucleation due to the stress concentration. Meanwhile, at high strain amplitude (Δεt/2=1.6%), deformation inhomogeneity phenomena occur in the αp phase, a large number of dislocation tangles and dislocation debris form in the αp phase, and some dislocation pile-ups form in the αs phase instead of β matrix. Due to the elongated αp phase, it can improve the compatibility of alloy α phase and β phase deformation, and delay crack nucleation and propagation. Therefore, Ti-35421 alloy has excellent low cycle fatigue performance.
AB - Low cycle fatigue (LCF) behavior of Ti-3Al-5Mo-4Cr-2Zr-1Fe (Ti-35421) alloy with bimodal microstructure consisting of lath α(αp) and βtrans was investigated by strain-controlled mode at room temperature. Results indicate that cyclic stress amplitudes of the Ti-35421 alloy with bimodal microstructure show cyclic softening at first, then reach to cyclic stability at high strain amplitude (Δεt/2=1.0%, 1.2%, 1.4%, 1.6%). However, the cyclic stress response characterizes cyclic saturation at low strain amplitudes (Δεt/2=0.6%, 0.8%). Only one fatigue crack source is found by fracture morphology observation when Δεt/2=0.6%, while a large number of small secondary cracks occur on the surface. On the contrary, multiple fatigue crack sources generate when the strain amplitude increases to 1.6%. The number of secondary cracks reduces, but the length and width of the secondary cracks increase significantly. TEM results indicate that a large number of dislocations generate at the αp/βtrans interface at the low strain amplitude (Δεt/2=0.6%), which leads to micro-crack nucleation due to the stress concentration. Meanwhile, at high strain amplitude (Δεt/2=1.6%), deformation inhomogeneity phenomena occur in the αp phase, a large number of dislocation tangles and dislocation debris form in the αp phase, and some dislocation pile-ups form in the αs phase instead of β matrix. Due to the elongated αp phase, it can improve the compatibility of alloy α phase and β phase deformation, and delay crack nucleation and propagation. Therefore, Ti-35421 alloy has excellent low cycle fatigue performance.
KW - Cyclic softening
KW - Cyclic stability
KW - Low cost titanium alloy
KW - Low cycle fatigue
UR - http://www.scopus.com/inward/record.url?scp=85103217226&partnerID=8YFLogxK
M3 - 文章
AN - SCOPUS:85103217226
SN - 1002-185X
VL - 50
SP - 588
EP - 594
JO - Xiyou Jinshu Cailiao Yu Gongcheng/Rare Metal Materials and Engineering
JF - Xiyou Jinshu Cailiao Yu Gongcheng/Rare Metal Materials and Engineering
IS - 2
ER -