CAJ | 학술논문

分别采用搅拌摩擦焊和冷金属过渡焊进行铝合金与镀锌钢的焊接试验，通过对焊缝截面显微组织、界面层成分及显微硬度的对比分析，研究影响焊接接头拉剪载荷和失效形式的因素。结果表明：搅拌摩擦焊接头的拉剪载荷接近于母材，焊缝晶粒细小、组织致密，显微硬度高于冷金属过渡焊接头，铝合金-钢异种金属界面层的结合为通过“洋葱瓣”状结构的机械咬合和冶金结合，界面层厚度约为20μm，为Al-Zn固溶体；冷金属过渡焊接头的拉剪载荷较铝母材降低了37．8％，在熔合线附近断裂，熔合线附近为柱状晶，焊缝根部存在热裂纹，显微硬度较铝母材的降低了30％，界面层厚度约为5μm，为Al-Fe金属间化合物。
분별채용교반마찰한화랭금속과도한진행려합금여도자강적한접시험，통과대한봉절면현미조직、계면층성분급현미경도적대비분석，연구영향한접접두랍전재하화실효형식적인소。결과표명：교반마찰한접두적랍전재하접근우모재，한봉정립세소、조직치밀，현미경도고우랭금속과도한접두，려합금-강이충금속계면층적결합위통과“양총판”상결구적궤계교합화야금결합，계면층후도약위20μm，위Al-Zn고용체；랭금속과도한접두적랍전재하교려모재강저료37．8％，재용합선부근단렬，용합선부근위주상정，한봉근부존재열렬문，현미경도교려모재적강저료30％，계면층후도약위5μm，위Al-Fe금속간화합물。
Friction stir welding (FSW)and cold metal transfer (CMT)were employed in dissimilar metal welding experiments of aluminum alloy and Zn-coated steel,and the effect of tensile-shear strength and failure modes were studied through the compari-sion of microstructure,micro hardness and interface layer.The results show that the tensile loads of FSW joints are close to base metal,grains are tiny,tissue is dandified,and CMT welding joints are reduced by 37.8%compared with aluminum base materi-al.Onion petal structures in FSW welding joints form a mechanical connection.The micro hardness is higher than CMT joints. The interface is connected by mechanical and metallurgical reaction.The Al-Zn solid solution thickness of interface is 20μm.The tensile-shear loads are reduced by 37.8%compared with Aluminum base metal.Fracture appears in the vicinity of the fusion line. The grains around the fusion line are columnar crystals.There is a hot crack at joint root,the micro hardness is reduced by 30%compared with base metal,and the Al-Fe intermetallic compound thickness of interface is about 5μm.