Microstructure Evolution and Mechanical Properties of Friction Stir Welded Al-Cu-Li Alloy  

作　　者：Peng Chen Wenhao Chen Jiaxin Chen Zhiyu Chen Yang Tang Ge Liu Bensheng Huang Zhiqing Zhang 

机构地区：[1]School of New Energy and Materials,Southwest Petroleum University,Chengdu 610500,China [2]Sichuan Provincial Engineering Research Center of Advanced Materials Manufacturing Technology for Shale Gas High-Efficient Exploitation,Southwest Petroleum University,Chengdu 610500,China [3]College of Materials Science and Engineering,Chongqing University,Chongqing 400045,China [4]School of Mechatronic Engineering,Southwest Petroleum University,Chengdu 610500,China [5]School of Robot Engineering,Yangtze Normal University,Chongqing 408100,China

出　　处：《Acta Metallurgica Sinica(English Letters)》2024年第5期855-871,共17页金属学报（英文版）

基　　金：financially supported by the Natural Science Foundation of Sichuan Province(2023NSFSC0915);the Postdoctoral Research Project Special Fund of Sichuan Province and Natural Science Starting Project of SWPU(2023QHZ017).

摘　　要：The investigation concentrates on friction stir welded(FSW)Al-Cu-Li alloy concerning its local microstructural evolution and mechanical properties.The grain features were characterized by electron back scattered diffraction(EBSD)technology,while precipitate characterization was conducted by using transmission electron microscopy(TEM)aligned along[011]Al and[001]Al zone axes.The mechanical properties are evaluated through micro-hardness and tensile testing.It can be found that nugget zones exhibit finely equiaxed grains evolved through complete dynamic recrystallization(DRX),primarily occurring in continuous dynamic recrystallization(CDRX)and discontinuous dynamic recrystallization(DDRX).In the thermal-mechanically affected zone(TMAZ),numerous sub-structured grains,exhibiting an elongated morphology,were created due to partial DRX,signifying the dominance of CDRX,DDRX,and geometric dynamic recrystallization(GDRX)in this region.T_(1)completely dissolves in the nugget zone(NZ)leading to the formation of Guinier-Preston zones and increase ofδ′,β′and S′.Conversely,T_(1)partially solubilizes in TMAZ,the lowest hardness zone(LHZ)and heat affected zone(HAZ),and the residual T_(1)undergoes marked coarsening,revealing various T_(1)variants.The solubilization and coarsening of T_(1)are primary contributors to the degradation of hardness and strength.θ′primarily dissolves and coarsens in NZ and TMAZ,whilst this precipitate largely coarsens in HAZ and LHZ.σ,TB,grain boundary phases(GBPs)and precipitate-free zone(PFZ)are newly generated during FSW.σexists in the TMAZ,LHZ and HAZ,whereas TB nucleates in NZ.GBPs and PFZ mostly develop in LHZ and HAZ,which can cause strain localization during tensile deformation,potentially leading to LHZ joint fracture.

关 键 词：Al-Cu-Li alloy Friction stir welding Microstructure evolution Mechanical properties 

分 类 号：TG142.1[一般工业技术—材料科学与工程]