Thermoelectric Magnetohydrodynatic Effects On Dictional Solidification Structure Of Al-Cu Alloy

Because of thermoelectric effects, a local current density appears in dendritic network during the solidification of a liquid metallic alloy. Thus, when a magnetic field is applied, a Lorentz force is created. Two alloys of Al-4.5%Cu and Al-33.2%Cu are solidified directionally in the vertical configuration under a transverse magnetic field with the result that this force enforces fluid flow. The experimental results show that the stronger the flow is, the coarser the dendrite is and the bigger the arm spacing is. Moreover, as the solidification rate increases, the influence of the convection on the dendrite becomes weak. When the magnetic field strength is constant, the dendrite becomes thinner and the arm spacing smaller as the solidification rate becomes bigger. Finally, we establish the moddeling of current which lies in the interface of phase and fluid.