Effect Of Unipolar Rectangle Wave Pulse Current On Solidification Structure Of Al-Cu Alloy

In this article, the effect of rectangle wave pulse current on non-directional and unidirectional solidification processing and structure of hypoeutectic and hypereutectic (Al-Cu) alloys were experimentally investigated.The effect of entropy of vibration on the dynamics of forming nucleus of solidification processing was discussed and a expression for the rate of forming nucleus during solidifying was put forward. Results show that:The pulse current with optimum combination of electric parameters (frequency, current amplitude and duration) all could result in the refinement of primary phase and solidification structure of (Al-Cu) alloys.Under action of pulse current, the drift of magnetic field gradient and the drift of curvature of magnetic line formed form the heterogeneity of magnetic field resection the migration Al⁺ and Cu⁺ along the direction of magnetic field, and then promote the dominate growth of Al₂ Cu Faceted crystals along the direction of magnetic field under the action of pulse current.(Al-Cu) alloys is a materials with better thermoelectric characters, the influence of seebeck effect and peltier effect on the solidification processing and structure were investigated, these thermoelectric effects all have influence on the stability of solid/liquid interface during solidification processing.