Impact of travel speed on the microstructure and mechanical properties of adjustable-gap bobbin-tool friction stir welded Al–Mg joints  

作　　者：Dong Wu Wen-ya Li Yan-jun Gao Jun Yang Quan Wen Nektarios Vidakis Achillefs Vairis 

机构地区：[1]State Key Laboratory of Solidification Processing,Shaanxi Key Laboratory of Friction Travel Technologies,Northwestern Polytechnical University,Xi'an 710072,China [2]Capital Aerospace Machinery Company,Beijing 100076,China [3]Department of Mechanical Engineering,Hellenic Mediterranean University,Heraklion,Crete 71004,Greece

出　　处：《International Journal of Minerals,Metallurgy and Materials》2021年第4期710-717,共8页矿物冶金与材料学报（英文版）

基　　金：financially supported by the State Key Laboratory of Solidification Processing (Northwestern Polytechnical University, China) under Grant 2019-QZ-01。

摘　　要：The butt welds of 4-mm thick 5A06 aluminum alloy plates were produced by adjustable-gap bobbin-tool friction stir travel with travel speeds of 200, 300, and 400 mm/min in this study.The microstructure was studied using optical microscopy and electron backscatter diffraction(EBSD).Tensile tests and microhardness measurements were performed to identify the effect of the travel speed on the joint mechanical properties.Sound joints were obtained at 200 mm/min while voids were present at different positions of the joints as the travel speed increased.The EBSD results show that the grain size, high angle grain boundaries, and density of geometrically necessary dislocations in different regions of the joint vary depending on the recovery and recrystallization behavior.Specific attention was given to the relationship between the local microstructure and mechanical properties.Microhardness measurements show that the average hardness of the stir zone(SZ) was greater than that of the base material, which was only affected slightly by the travel speed.The tensile strength of the joint decreased with increasing travel speed and the maximal strength efficiency reached 99%.

关 键 词：friction stir welding bobbin-tool aluminum alloy microstructure mechanical properties adjustable-gap 

分 类 号：TG453.9[金属学及工艺—焊接]