Simulation And Preparation Studies On Continuous Casting Of Cladding Aluminum Alloys Under Direct Current Magnetic Field

Clad material as a new type of material, has become one of research focuses in material field. Since the clad material has a series of merits of high hardness, corrosion resistance, and high electric conductivity, it has been widely applied in the fields of aerospace, oil, machinery, chemical industry, automobile and shipbuilding. In this paper, a direct current magnetic field is used to control the flow and solidification of aluminum liquid, by which different compositions of aluminum liquids (3003/4004) can solidify together to form a cladding slab with different left and right properties.In order to verify the feasibility of electromagnetic braking, the Fluent^TM software is used to simulate the flow field distribution of double flow pouring. The results show that horizontal electromagnetic field can effectively inhibit the velocity of liquid flow at the sprue and reduce the jet penetration depth. The recirculation zone occurred at the center of casting model is also inhibited.The distribution of three-dimensional magnetic field is calculated with the use of ANSYS^TM software. Magnetic induction intensity increases with the increasing of electric current, and it reaches its maximum of 0.3T when current intensity is 136A. The magnetic induction intensity is distributed evenly at the direction (X) of slab width. The magnetic induction intensity distributes as a waved mountain at the direction (Y) of slab drawing, reaches its maximum at the magnetic pole center and decays gradually toward the edge. The magnetic induction intensity distributes as a parabola at the direction (Z), reaches its maximum at the wall of mold. Meanwhile, the magnetic induction intensity in the mold is measured by the Tesla-Meter, and the measured result is well matched with the calculated one.In order to determine the parameters of continuous casting process, the influence of heat flux density, pouring temperature, drawing speed on temperature field, distribution of liquid fraction and velocity field in continuous casting process of cladding cast slab is numerically analysed with the use of VOF Multiphase Flow in Fluent^TM software. The results show that when heat flux density is less than 2.5×10⁵W/m², it is hard to form a stable solidification shell at the side of 3003 aluminum alloy; when the heat flux density is too high, the two kinds of liquid metal will weld the water cooled divider; the pouring temperature should be controlled to be as low as possible, however, if the pouring temperature is too low, slab-drawing can not go well; when drawing speed is no less than 0.002m/s, it will make the two kinds of metal liquid badly mixed and cause break out. The sump shape of 4004 side is measured and simulated and the measured result is well matched with the calculated one.In the experiments, some apparatuses are designed, such as gating system and water cooled divider. With the use of process parameters provided by numerical simulation, cladding slab of 3003/4004 aluminum alloy with clear interface and high binding strength is successfully made. The cladding slabs have been carried out metallographic analysis.