TY - JOUR
T1 - Short crack growth behavior and its transitional interaction with 3D microstructure in Ti-6Al-4V
AU - Hassanipour, M.
AU - Watanabe, S.
AU - Hirayama, Kyosuke
AU - Toda, H.
AU - Uesugi, K.
AU - Takeuchi, A.
N1 - Funding Information:
The synchrotron radiation experiments were performed at SPring-8 with the approval of Japan Synchrotron Radiation Research Institute (JASRI) through proposal number of 2016A0076 and 2016B0076. This work was supported by the Grant-in-aid from Structural Materials for Innovation (SM4I) of the Cross-ministerial Strategic Innovation Promotion Program (SIP) of Japan. The authors gratefully acknowledge the support of Light Metal Educational Foundation (LMEF).
Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2018/12/19
Y1 - 2018/12/19
N2 - Currently, short crack growth behavior and rate variations are not well understood in the literature. This is due to lack of studies regarding the interaction between 3D short crack and microstructure and its effect on crack growth. In order to study this interaction, in situ computed tomography was performed to measure crack growth at sub-grain level (every 5 µm) during a fatigue test in a bimodal Ti-6Al-4V alloy for two crack front regions. This was followed by serial sectioning coupled with electron backscattering diffraction (EBSD) to identify the short crack growth in the microstructure, i.e. α α + β phases and interface. Results show that crack growth has the highest rate in α phase as compared to the α + β phase and the interface in both regions. The crack grows preferably into α phase when compared to the average microstructural fraction in the first region, but it decreases below this fraction in the second region. The crack grows mainly close to crystallographic planes in α grains with the maximum shear stress (favorable planes) in the first region. As the short crack grows into the second region, there is an increase in number of grains enclosed in the plastic zone size. As a result, there is a decrease in the mismatch angle between neighboring cracked grains, which leads to higher deviation from favorable planes causing a local variation in crack growth rate.
AB - Currently, short crack growth behavior and rate variations are not well understood in the literature. This is due to lack of studies regarding the interaction between 3D short crack and microstructure and its effect on crack growth. In order to study this interaction, in situ computed tomography was performed to measure crack growth at sub-grain level (every 5 µm) during a fatigue test in a bimodal Ti-6Al-4V alloy for two crack front regions. This was followed by serial sectioning coupled with electron backscattering diffraction (EBSD) to identify the short crack growth in the microstructure, i.e. α α + β phases and interface. Results show that crack growth has the highest rate in α phase as compared to the α + β phase and the interface in both regions. The crack grows preferably into α phase when compared to the average microstructural fraction in the first region, but it decreases below this fraction in the second region. The crack grows mainly close to crystallographic planes in α grains with the maximum shear stress (favorable planes) in the first region. As the short crack grows into the second region, there is an increase in number of grains enclosed in the plastic zone size. As a result, there is a decrease in the mismatch angle between neighboring cracked grains, which leads to higher deviation from favorable planes causing a local variation in crack growth rate.
UR - http://www.scopus.com/inward/record.url?scp=85054289984&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85054289984&partnerID=8YFLogxK
U2 - 10.1016/j.msea.2018.09.073
DO - 10.1016/j.msea.2018.09.073
M3 - Article
AN - SCOPUS:85054289984
SN - 0921-5093
VL - 738
SP - 229
EP - 237
JO - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
JF - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
ER -