Interfacial microstructures and mechanical property of vaporizing foil actuator welding of aluminum alloy to steel

Different from traditional collision welding methods in driving principle, vaporizing foil actuator welding (VFAW) was developed to weld 3003 aluminum alloy (Al) to 4130 steel (Fe). The interfacial morphology and microstructures of VFAW were investigated, and the effect of the impact angle on interfacial morphology was analyzed through a groove die with a special angle. Results showed that irregular interfacial waves were formed between Al and Fe, confirming that the VFAW achieved metallurgical bonding. The range of impact angle forming interfacial irregular waves was from 8° to 24°, which meant the impact welding of 3003 Al to 4130 Fe has relatively wide weldable range of collision angle. The formation of irregular interfacial waves considered to be related to match between the density of the flyer and the ultimate static strength of the target. A very thin layer with intermetallic compounds, composed of continuous Al86Fe14 and massive Fe4Al13 and FeAl, was formed in the trough of interfacial waves. The layer with intermetallic compounds was formed by very thin liquid metal, which was the residual liquid metal of the jet flow along the interface. The highest anti-shear capacity of the joint exceeds 200 N/mm.