AZ31B鎂合金CMTCycleStep焊接接頭組織和性能研究

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中圖分類號：TG444 文獻標志碼：B DOI：10.19710/J.cnki.1003-8817.20240407

Research on the Microstructure and Properties of AZ31B Magnesium Alloy CMT Cycle Step Welded Joint

Huang Changjun'， Tang Weineng'，Wu Lei'， Han Mingming2 （1.TechnologyCente，BaosteelMetalCo.，td.，hanghaOo94O;2.WeldingBusinessUnit，F(xiàn)ronusItellgentEqipt （Shanghai） Co.，Ltd.， Shanghai 200940）

Abstract：This paper investigates the microstructure，mechanical properties and elemental distribution of welded joints using the CMT Cycle Step process with AZ81 filer wire for AZ31B magnesium aloy extruded plates to develop newwelding technologiesfor magnesium aloys.Comprehensive characterization isperformed throughoptical microscopy，Vickers hardness tester，tensile testing machine，Scaning Electron Microscopy （SEM）and EnergyDispersive X-ray Spectroscopy （EDS）.Theexperimental results demonstratethatuniformand regular fish-scale patterns are formed on the weld surface.The weld zone primarily consists of α-Mg phase with discontinuous eutectic structures at grainboundaries.WhileZnelement distribution shows no significant concentration diferenceacross the base metal，fusion zone，andweld zone，Al element exhibitsmarkedly higherconcentration intheweld region compared tothe base material.The maximum hardness is observedinthe weld zone，with adistinct softening phenomenon characterizedbysignificant hardnessreduction intheHeat-Affected Zone （HAZ）.The tensilestrengthof the welded joint reaches levels comparable to the base material.Tensile fractures occur in the HAZ，presenting pure shear fracture surfaces with morphological features indicative of ductile fracture characteristics.

Keywords：Magnesiumalloy，CMTCycle Stepprocess，Metallographic structure，Mechanical properties， Fracture morphology

1前言

的比強度和比剛度、良好的阻尼性能、可循環(huán)再利用性、較好的電池屏蔽性和優(yōu)異的加工性能，在航空航天、交通運輸、3C電子、軍工和能源等領(lǐng)域展鎂合金作為最輕的金屬結(jié)構(gòu)材料，具有較高現(xiàn)出廣闊的應用前景[1-3]。（剩余6115字）