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Influences of Friction Stir Welding and Post‐Weld Heat Treatment on Al–Cu–Li Alloy
Author(s) -
Lin Yi,
Lu Change,
Wei Chengyang,
Zheng Ziqiao
Publication year - 2018
Publication title -
advanced engineering materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 114
eISSN - 1527-2648
pISSN - 1438-1656
DOI - 10.1002/adem.201700652
Subject(s) - materials science , softening , friction stir welding , welding , alloy , metallurgy , ultimate tensile strength , microstructure , severe plastic deformation , heat affected zone , ductility (earth science) , recrystallization (geology) , precipitation , slip (aerodynamics) , composite material , creep , paleontology , physics , meteorology , biology , thermodynamics
In this paper, the influences of friction stir welding (FSW) and post‐weld heat treatment (PWHT) on the microstructures and tensile properties of Al–Cu–Li alloy are investigated. After FSW, strengthen loss occurred in the welding area. Remarkable softening occurs in the thermo‐mechanically affected zone (TMAZ) resulting from dissolution of Al 3 Li ( δ ′) phases. Recrystallization and precipitation of ultra‐fine δ ′ phases take place in the nugget zone (NZ) that lightens the softening degree of this zone. A noteworthy enhancement in the hardness and tensile strength of the joint is achieved after T8 reaging treatment (3% − pre‐deformation, 30 h at 152 °C). However, re‐solution treatment coupled with re‐aging treatment leads to ductility deterioration in the joint because coplanar slip of coarse Al 3 Li phases induces severe stress concentration during plastic deformation.