The influence of Zn interlayer on the microstructure and mechanical properties of FSLW 6061 aluminum alloy with 2 mm thick and T2 copper thin plate joints was investigated by adopting pure Zn with 30μm thick as pre-setting interlayer.The results reveal that Al and Cu dissimilar metals can be welded together with the addition of Zn interlayer.At a plunge depth of 0.1 mm

the joint exhibits the satisfied bonding quality with absence of welding defects

and the maximum tensile load reaches about2.8 kN.The joint load is decreased slightly with increasing in the plunge depth（0.2 mm）due to the increase of hook defects size resulting in decrease of effective plate thickness.As the plunge depth increased to 0.3 mm

the more welding defects can be formed in the joints.Zn interlayer can promote the alloying reaction between Al and Cu substrates in the hook zone to form an Al-Cu diffusion layer with a thickness of about 4μm

decreasing the detrimental effect of hook defects on the joint and increasing the effective bonding area

thus improving the joint quality.