镁铝异种金属搅拌摩擦焊接头微观组织和力学性能分析

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中图分类号：TG456.9 文献标识码：A DOI：10.7535/hbkd.2026yx01002

Abstract：To suppress theformation britle magnesium-aluminum intermetaliccompounds（IMCs）in the welding joints magnesium-aluminum dissmilar metals enhance the joint performance，a friction stir welding（FSW）technique was adopted copper foil was usedasan interlayer metal toweld7075-T6aluminum aloyAZ31Bmagnesium alloy.A comprehensive suiteanalytical techniques，including microstructural characterization，energy-dispersivespectrometer （EDS），X-ray diffractometer（XRD），hardness testing， sheartesting wereemployed to systematicall investigate the microstructural evolution mechanical properties the magnesium/aluminum dissimilar metal joints withwithout the copperinterlayer.Theexperimental resultsrevealthattheincorporationacopper interlayer intheweld nugget zone establishes aternarymagnesium-aluminum-copperdiffusionsystemThissystem efectivelysuppesss interdifusionbehavior between magnesium aluminum，which reduces the diffusion layer thicknessin the weld nugget zone from 150μm to 50 μm.Simultaneously，newdifusionlayersareformedonboth sides thehook-shapeddefects incopper-containingjoints that efectively suppresss theformation magnesium-aluminum IMCs，whilepromoting the formation copper-magnesium copper-aluminum IMCs.Meanwhile，the incorporation thecopper interlayer significantly reduces the area hook-shaped defectsat thejoint interfaceefectivelymitigatesstressconcentrationattheinterface.Ultimately，comparedto conventional joints，thefracture pathcopper-containing jointsischangedfrom the IMCs layer totheweldnuggetzone. Average shear strength the joints increases from 3 4O7 N to 4615N ，representinga 35.5% improvement in shear performance.The studyidentifiesthecausesfortheimprovementthemechanicalpropertiescertain magnesium/aluminum dissimilar metals joints through FSW，providing reference for welding other dissimilar materials.

keywords：material surface interface；magnesium/aluminum disimilar metal；friction stirwelding;copperfoil inter layer；joint diffusion behavior

搅拌摩擦焊（friction stir welding，FSW）相较于其他焊接方法，能够精确控制焊接过程中的热输入，减少因异种金属物理性质的差异导致的焊接缺陷，改善焊接接头力学性能，因此被广泛应用于低熔点金属和异种金属的焊接[1]。（剩余12421字）