Electromagnetic Fields On The Za27 Alloy And Al-si Alloy Solidification Organizational Impact Of Experimental Research

In this article, by use of a rotating electromagnetic field (REMF) equipment, a pulse current equipment and a device of solidification experiment matched for the power sources, the effects of REMF, pulse current and (REMF + pulse current) superposed field on the solidification process and solidification microstructure of ZA27 alloy, Al-7wt%Si hypoeutectic alloy and Al-12.39wt % Si near-eutectic alloy were researched experimentally.Focusing on ZA27 alloy, the mechanism of upstream growthing of columnar crystal on the surface layer of the cylindrical sample and the bore force state of melt caused by the flowing of the melt were analyzed during the solidification processing under the effect of the REMF, and then the mechanism of transformation from dendritical to globular crystal was discussed under the action condition of the alternative REMF.Based on the effect of shock wave, which was generated by pulse current, on the structure of liquid metal, the effect of current convergence effect and the Peltier effect on the solidification interface morphology and the changing of the flow state of melt in the solidification region caused by the electromagnetic force, the refinement mechanism of the effect of triangle pulse current on the solidification microstructure of the Al-7wt%Si hypoeutectic alloy and the Al-12.39wt%Si near-eutectic alloy were analyzed and discussed. At the same time, the effect of pulse current on the orientation of a-Al phase in Al-12.39wt%Si near-eutectic alloy during solidification processing was discussed preliminary.The effect of (REMF + pulse current) superposed field on the solidification microstructure of Al-7wt % Si hypoeutectic alloy was studied tentatively. The experimental results appeared that it had favorable inoculation and modification actions to the solidification structure. The produce of the electromagnetism ultrasonic was discussed preliminary.The experiment results showed that imposed the pulse current and the REMF could present favorable actions to solidification processing and microstructure of alloys. The various effects, which were caused by pulse current and the REMF in melt, made the solidification microstructure and the orientation of crystals change and the refinement effect of grains was more notable under the actions of (pulse current and REMF ) superposed field. The existing study results showed that in the field of materials science and Engineering the application of electric field and electromagnetic field will be likely to satisfy the requests of the advanced solidification technology and advanced materials. As the research goes on, it could realize the span from laboratory scale to practical application, and will become an advanced technology for the solidification control.