Al/Steel Tubular Bimetallic Structure Fabricated by Rotary Wire Arc Surfacing
摘要
In this study, wire arc rotary surfacing of 4043 Al on a 1 mm thick 304 stainless steel tube was conducted. By electroplating pretreatment of the steel surface and designing water cooling for heat dissipation, good weld overlay formation can be achieved. The Zn coating can improve the wetting of aluminum droplets on stainless steel surfaces, while the Ni coating layer can prevent the solid/liquid reaction between Fe/Al and reduce the formation of brittle intermetallic compounds (IMCs) at the interface. The Ni coating layer dissolved and diffused into the molten Al during welding. When the Ni layer was completely dissolved, Fe(Al, Si)3 compound was formed at the interface, whereas the residual Ni layer induced the formation of the Al3Ni compound. The parameters with the flattest cladding morphology and the highest bonding strength were a cooling water temperature of 25 °C, a cooling water flow rate of 100 ml/min, a welding current of 75 A, and a welding voltage of 12 V. The joint with a Ni + Zn composite coating had a highest shear strength of 102.55 MPa. The optimal matching relationship between the cooling water flow rate and the cooling water temperature was established by adjusting the welding heat input and water cooling rate.