| Magnesium alloy and aluminum alloy are both energy saving and environmental friendly light alloy materials.Magnesium alloy is lighter but has lower corrosion resistance,while aluminum alloy has higher strength and good corrosion resistance but higher mass density than magnesium alloy.The application of magnesium alloy and aluminum alloy together can achieve more light weight and corrosion resistance effect.Therefore,the numerical simulation and experimental study on the forming mechanism of AZ31/1060 magnetic pulse welding interface in this paper is of great significance for promoting the wide application of magnesium alloy/aluminum alloy welded structure.In this paper,the working current model of magnetic pulse welding was established according to Thevannin's theorem,and the transient analysis model of magnetic pulse welding process was established based on Anys Maxwell electromagnetic field simulation software.The magnetic field intensity,current density,ohmic loss and the induced current,force density and velocity of the flyboard in the magnetic pulse welding coil with the cross-sectional area of 8x10 mm and 4x10 mm were numerically simulated.The collision model of fly plate and substrate in magnetic pulse welding was established based on Auto Dyn,and the forming process of magnetic pulse welding interface was numerically simulated.The AZ31/1060 magnetic pulse welding process test was carried out to test the microhardness of the magnetic pulse welding interface,observe the magnetic pulse welding interface morphology,and analyze the diffusion process of magnesium and aluminum elements at the magnetic pulse welding interface,as well as the formation mechanism of adiabatic shear band and vortex.The results show that the magnetic field intensity,current density and ohmic loss of magnetic pulse welding increase by 45%,35% and 59%,respectively,when the coil size decreases.The induced current density and physical force density of magnetic pulse welded fly-plate increased by 25% and 18% respectively with the decrease of welding coil size.The8x10 mm coil is determined as the magnetic pulse welding process test coil.The shear forces on the magnesium alloy side and the aluminum alloy side of the magnetic pulse welding interface show positive and negative symmetrical distribution,and the maximum absolute value is 0.1097 GPa.The lateral plastic strain rate of magnesium alloy is 300%,and that of aluminum alloy is 160%.The magnetic pulse welding interface is corrugated,and the simulation results of magnetic pulse welding interface are consistent with the experimental results.The adiabatic shear bands are formed on both sides of the magnetic pulse welding interface under the action of shear force,and the simulation results of shear force distribution agree with the experimental results.The deformation of the magnesium alloy side of the magnetic pulse welding interface is greater than that of the aluminum alloy side,and the plastic strain rate simulation is in good agreement with the experiment.The appearance of vortex shape indicates the phenomenon of jet flow and metal melting,which is consistent with the simulated phenomenon. |
PDF Full Text Request