In order to study the interface characteristics and microstructure formation of Ti-Al composite plate, explosive welding was carried out with TA2 titanium as the fly plate and 5083 aluminums as the base plate. Optical microscope and electron microscope were used to analyze the microstructure of intermetallic compounds. SPH method was used to simulate the welding process of composite plates. The formation conditions and initial defects of intermetallic compounds were analyzed. The results show that most of the melted metal in the wave-front stays in the wave-waist region, and there was a relative velocity difference between the vortex and the titanium tissue, which led to the existence of small pieces of fragmentation. The outer layer of the vortex had higher velocity than the inner layer. The formation of Ti 3 Al, its antioxidant capacity wound lead to the formation of cracks. The temperature of outer vortex was higher than that of inner vortex, and the vortex has a transition layer of 5 μm, which is thinner than the transition layer of 8 μm between cladding plate and substrate. The jet was mostly composed of aluminum metal, and the interface jet velocity reaches 3000 m•s -1 and the interface temperature reaches up to 2100 K. Compared with the molten metal in the wave-back vortex, the jet temperature at the interface was higher, resulting in a thicker transition layer at the bonding surface. The residual stress at the interface wound cause the density of the material to increase.

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In order to reduce critical impact velocity and enlarge weldability window of aluminium/steel explosive welding, a chemical copper plating layer as interlayer was proposed to carry out aluminium/steel explosive welding. The results showed that the interface of the 1060/Q235 composite plate had good bonding performance, and no obvious defects such as cracks and pores were found. Copper plating as intermediate layer could enlarge aluminium/steel weldability window. The thickness of solidified melt was much thicker than that of diffusion zone. The molten copper particles participated in the formation of re-entry jet, which rotated under the action of initial jet. The presence of the Cu layer reduces the occurrence of excessive melting during welding and improves the properties of the interface.

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