Strengthening strategy for high-performance friction stir lap welded joints based on 5083 Al alloy  

作　　者：Yujia Shen Jijie Wang Beibei Wang Peng Xue Fengchao Liu Dingrui Ni Bolv Xiao Zongyi Ma 

机构地区：[1]College of Material Science and Engineering,Shenyang Aerospace University,Shenyang 110136,China [2]Shi-changxu Innovation Center for Advanced Materials,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China [3]CAS Key Laboratory of Nuclear Materials and Safety Assessment,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China [4]Binzhou Institute of Technology,Shandong Key Laboratory of Advanced Aluminium Materials and Technology,Weiqiao-UCAS Science and Technology Park,Binzhou 256606,China [5]Centre of Excellence for Advanced Materials,Dongguan 523808,China

出　　处：《International Journal of Minerals,Metallurgy and Materials》2024年第11期2498-2507,共10页矿物冶金与材料学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.52305436 and 51975553);the Program for Guangdong Basic and Applied Basic Research Foundation,China(No.2021A151511006);Guangxi Science and Technology Major Program,China(No.AA23023029);Liaoning Natural Science Foundation of China(No.2021-MS-007);the Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.Y2021061);the Bintech-IMR R&D Program(No.GYYJSBU-2022-002);the Institute of Metal Research Innovation Found,China(No.2022-PY11).

摘　　要：During aircraft,ship,and automobile manufacturing,lap structures are frequently produced among Al alloy skins,wall panels,and stiffeners.The occurrence of welding defects severely decreases mechanical properties during friction stir lap welding(FSLW).This study focuses on investigating the effects of rotation rate,multipass welding,and cooling methods on lap defect formation,microstructural evolution,and mechanical properties.Hook defects were eliminated by decreasing welding speed,applying two-pass FLSW with a small welding tool,and introducing additional water cooling,thus leading to a remarkable increase in effective sheet thickness and lap width.This above strategy yielded defect-free joints with an ultrafine-grained microstructure and increased tensile shear force from 298 to 551 N/mm.The fracture behavior of FSLW joints was systematically studied,and a fracture factor of lap joints was proposed to predict their fracture mode.By reducing the rotation rate,using two-pass welding,and employing additional water cooling strategies,an enlarged,strengthened,and defect-free lap zone with refined ultrafine grains was achieved with a quality comparable to that of lap welds based on 7xxx Al alloys.Importantly,this study provides a valuable FSLW method for eliminating hook defects and improving joint performance.

关 键 词：friction stir lap welding defect control microstructure fracture mechanisms mechanical properties 

分 类 号：TG453.9[金属学及工艺—焊接]