TY - JOUR
T1 - Local Deformation and Fracture Behavior of High-Strength Aluminum Alloys Under Hydrogen Influence
AU - Shimizu, Kazuyuki
AU - Toda, Hiroyuki
AU - Uesugi, Kentaro
AU - Takeuchi, Akihisa
N1 - Funding Information:
This research was supported by the Japan Science and Technology Agency (JST) under Collaborative Research Based on Industrial Demand “Heterogeneous Structure Control: Towards Innovative Development of Metallic Structural Materials.” This research was supported in part by a grant from the Light Metal Educational Foundation, Japan. The synchrotron radiation experiments were performed at the BL20XU and the BL37XU of SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute (JASRI) (Proposal Nos. 2016A1199, 2016B1081, 2016A0076, 2016B0076). The authors also thank Dr. Takahiro Shikama in KOBELCO and the Japan Aluminium Association for providing and preparing the materials used.
Publisher Copyright:
© 2019, The Minerals, Metals & Materials Society and ASM International.
PY - 2020/1/1
Y1 - 2020/1/1
N2 - The local deformation and fracture behavior of high-Zn Al-Zn-Mg(-Cu) alloys under hydrogen influence were investigated by in situ tests through synchrotron X-ray tomography. Intergranular and quasi-cleavage fractures were induced by hydrogen, and strain localization by the presence of cracks was not observed by 3D strain mapping. These results suggest that the strain localization at the crack tip is smaller than the measurement limit of 3D strain mapping. The average crack-tip-opening displacements, which are one of the crackdriving forces specified by fracture mechanics, directly measured from the tomographic slice were 0.14 and 0.23 μm for intergranular cracks and quasi-cleavage cracks, respectively. The crack driving forces of the intergranular and quasi-cleavage cracks were small. The local deformation behavior at the crack tips was analyzed based on fracture mechanics. The local deformation field of the crack tip, which was characterized using the Rice–Drugan–Sham (RDS) solution rather than the Hutchinson–Rice–Rosengren (HRR) solution, was located within 20 μm of the crack tip, and its size was limited. The results of this work clarify that the intergranular and quasi-cleavage crack growths are caused by small driving forces; however, this behavior is not perfectly brittle, accompanying local deformation at the crack tip.
AB - The local deformation and fracture behavior of high-Zn Al-Zn-Mg(-Cu) alloys under hydrogen influence were investigated by in situ tests through synchrotron X-ray tomography. Intergranular and quasi-cleavage fractures were induced by hydrogen, and strain localization by the presence of cracks was not observed by 3D strain mapping. These results suggest that the strain localization at the crack tip is smaller than the measurement limit of 3D strain mapping. The average crack-tip-opening displacements, which are one of the crackdriving forces specified by fracture mechanics, directly measured from the tomographic slice were 0.14 and 0.23 μm for intergranular cracks and quasi-cleavage cracks, respectively. The crack driving forces of the intergranular and quasi-cleavage cracks were small. The local deformation behavior at the crack tips was analyzed based on fracture mechanics. The local deformation field of the crack tip, which was characterized using the Rice–Drugan–Sham (RDS) solution rather than the Hutchinson–Rice–Rosengren (HRR) solution, was located within 20 μm of the crack tip, and its size was limited. The results of this work clarify that the intergranular and quasi-cleavage crack growths are caused by small driving forces; however, this behavior is not perfectly brittle, accompanying local deformation at the crack tip.
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U2 - 10.1007/s11661-019-05304-y
DO - 10.1007/s11661-019-05304-y
M3 - Article
AN - SCOPUS:85066970679
SN - 1073-5623
VL - 51
SP - 1
EP - 19
JO - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
JF - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
IS - 1
ER -