电焊机2025，Vol.55Issue(11)：1-9,9.DOI:10.7512/j.issn.1001-2303.2025.11.01
LA81双相镁锂合金搅拌摩擦焊接头耐腐蚀性能研究
Study on Corrosion Resistance of Friction Stir Welded LA81 Mg-Li Dual-Phase Alloy Joints
摘要
Abstract
LA81 Mg-Li alloy is an ideal material for aerospace lightweight applications due to its low density,high specific strength,and excellent damping capacity.In this study,friction stir welding(FSW)butt welding was performed on 2 mm-thick LA81 Mg-Li alloy plates using different tool rotational speeds(475-1 180 r/min)and welding speeds(47.5-118 mm/min).The aim was to investigate the influence of FSW parameters on the on the the microstructure and corrosion resistance of the joints,as well as to analyze the relationship between the corrosion mechanism and microstructural evolution.Electro-chemical tests revealed that at a constant tool rotational speeds of 475 r/min,the sample welded at a welding speed of 60 mm/min exhibited the highest corrosion resistance,with a corrosion current density of 2.494 8×10-4 μA/cm2,which is 19.9%lower than that of the base material(3.116 02×10-4 μA/cm2).Microstructural analysis indicated that the weld nugget zone(WNZ)consisted of fine recrystallized grains(size<5 μm)resulting from dynamic recrystallization during FSW,which con-tributed to shallow and sparse corrosion pits.In contrast,the thermo-mechanically affected zone(TMAZ)exhibited coarse grains and continuous networks of β-Li phase,leading to pronounced intergranular corrosion and dissolution along phase boundaries.EDS results confirmed that corrosion initiated preferentially in the β-Li phases(Li-rich regions),accompanied by the formation of corrosion products such as Li2O.Long-term immersion tests showed that FSW joints maintained rela-tively intact surfaces after 72 h,whereas the base metal suffered severe exfoliation corrosion with pit diameters exceeding 70 μm within 48 h.It is concluded that FSW significantly enhances the corrosion resistance of LA81 Mg-Li alloy through grain refinement and optimization of dual-phase distribution.关键词
搅拌摩擦焊/双相镁锂合金/耐蚀性能/微观组织Key words
friction stir welding/duplex Magnesium-Lithium alloy/corrosion resistance/microstructur分类
金属材料引用本文复制引用
王楠,王守武,黄兴亮,陈长锐,陈玉华,胡杰,蒋青,郑敏..LA81双相镁锂合金搅拌摩擦焊接头耐腐蚀性能研究[J].电焊机,2025,55(11):1-9,9.基金项目
国家自然科学基金(52575394,52175326,52505386) （52575394,52175326,52505386）
江西省自然科学基金创新群体项目(20252BAC230001) （20252BAC230001）
