TY - JOUR
T1 - Failure mechanisms and low-cycle fatigue behavior of double-sided friction stir welded 6061-T6 aluminum alloy joints
T2 - influence of dual-tool interaction
AU - Su, Yu
AU - Zhou, Mengran
AU - Li, Wenya
AU - Yang, Xiawei
AU - Tang, Yishuang
AU - Wu, Dong
AU - Chen, Gaoqiang
AU - Shi, Qingyu
AU - Bergmann, Luciano
AU - Klusemann, Benjamin
N1 - Publisher Copyright:
© 2026 Elsevier Ltd.
PY - 2026/10/10
Y1 - 2026/10/10
N2 - This study presents a comparative failure analysis of low-cycle fatigue (LCF) behavior in 6061-T6 aluminum alloy joints fabricated by synergistically double-sided friction stir welding (SDS-FSW) and conventional sequentially double-sided friction stir welding (CDS-FSW). The cyclic deformation, damage evolution, and crack propagation characteristics were systematically evaluated under strain-controlled loading. Both joints exhibited elastic response at 0.15% strain amplitude and pronounced cyclic hardening beyond 0.25%. However, the CDS-FSW joints showed consistently lower peak stress amplitudes and reduced hardening capacity, indicating inferior resistance to cyclic deformation. Increasing strain amplitude accelerated plastic strain energy accumulation and fatigue damage. Despite exhibiting higher plastic strain energy density, SDS-FSW joints achieved longer fatigue life due to their improved microstructural uniformity and reduced crack growth rate. Fractographic analysis revealed that CDS-FSW joints exhibited larger fatigue striation spacing and more rapid crack propagation, whereas SDS-FSW joints showed finer striations and more stable ductile fracture characteristics. The results establish a direct link between welding-induced thermo-mechanical conditions and fatigue failure mechanisms, providing insights for durability assessment and structural reliability of double-sided friction stir welded aluminum components.
AB - This study presents a comparative failure analysis of low-cycle fatigue (LCF) behavior in 6061-T6 aluminum alloy joints fabricated by synergistically double-sided friction stir welding (SDS-FSW) and conventional sequentially double-sided friction stir welding (CDS-FSW). The cyclic deformation, damage evolution, and crack propagation characteristics were systematically evaluated under strain-controlled loading. Both joints exhibited elastic response at 0.15% strain amplitude and pronounced cyclic hardening beyond 0.25%. However, the CDS-FSW joints showed consistently lower peak stress amplitudes and reduced hardening capacity, indicating inferior resistance to cyclic deformation. Increasing strain amplitude accelerated plastic strain energy accumulation and fatigue damage. Despite exhibiting higher plastic strain energy density, SDS-FSW joints achieved longer fatigue life due to their improved microstructural uniformity and reduced crack growth rate. Fractographic analysis revealed that CDS-FSW joints exhibited larger fatigue striation spacing and more rapid crack propagation, whereas SDS-FSW joints showed finer striations and more stable ductile fracture characteristics. The results establish a direct link between welding-induced thermo-mechanical conditions and fatigue failure mechanisms, providing insights for durability assessment and structural reliability of double-sided friction stir welded aluminum components.
KW - 6061-T6 aluminum alloy
KW - Crack propagation characteristics
KW - Cyclic deformation
KW - Low-cycle fatigue
KW - Synergistically double-sided friction stir welding (SDS-FSW)
UR - https://www.scopus.com/pages/publications/105045260637
U2 - 10.1016/j.engfracmech.2026.112483
DO - 10.1016/j.engfracmech.2026.112483
M3 - 文章
AN - SCOPUS:105045260637
SN - 0013-7944
VL - 345
JO - Engineering Fracture Mechanics
JF - Engineering Fracture Mechanics
M1 - 112483
ER -