| Al-5Cu(wt.%)alloy belongs to aluminum copper alloy,which with good cutting and welding performance.But the casting performance and corrosion resistance is poor.Under certain conditions can produce intergranular corrosion.This kind of alloy has a wide application in aviation products,mainly used to bear big load of the structure and heat-resistant parts.Because of the complex physical changes including heat transfer,mass transfer and phase transformation during the solidification process of metal,electromagnetic stirring has gradually become an effective way to control solidification process with the gradual development and widespread use of electromagnetic stirring technology.Especially in the aspect of raising the equiaxed crystal rate of the billet,refining the microstructure and optimizing the inclusion and promoting the homogenization of the components,electromagnetic stirring has the key effect.In this paper,the electromagnetic field in the Al-5Cu(wt.%)alloy melt under the action of electromagnetic stirrer is simulated by means of numerical simulation and finite element analysis software Ansoft Maxwell.The two dimensional finite element calculation model of the self-made Al-5Cu(wt.%)alloy electromagnetic agitator involved in this paper is created.The magnetic field strength and electromagnetic force in the melt of Al-5Cu(wt.%)alloy were calculated under different experimental parameters of electromagnetic stirrer,and their distribution rules were analyzed,which provides a solid theoretical basis and basis for improving the technological parameters of electromagnetic stirrer.The magnetic field analysis results of numerical simulation of Al-5Cu(wt.%)alloy electromagnetic stirrer show that: when the power frequency of the electromagnetic agitator is the same,with the increase of excitation voltage,the magnetic induction intensity and electromagnetic force in the melt inner of Al-5Cu(wt.%)are increased.And that the farther the axis of Al-5Cu(wt.%)alloy melt is,the greater the magnetic induction force and electromagnetic force will be.The greater the magnetic induction and electromagnetic force in the Al-5Cu(wt.%)alloy melt,the more agitation of the Al-5Cu(wt.%)alloy melt.When the excitation voltage is certain,with the increase of the frequency of the power supply,there is no significant change in the magnetic induction intensity,but the magnetic force is increased and the variation along the radial direction is similar to the change of excitation voltage.The simulation results also show that when the power frequency is 35 Hz,the best excitation voltage range is 80~100 V.When the excitation voltage is 100 V,the best stirring power frequency range is 35~45 Hz.The test scheme was determined: the casting rods were obtained in the gravity field,that is,without electromagnetic stirring and different electromagnetic stirring parameters.The castings under different test conditions were sampled,and the metallographic structure was observed and compared.From the test conclusion,it can be seen that the solidification structure of Al-5Cu(wt.%)alloy is near equiaxed crystal under the influence of electromagnetic stirring.Compared with the solidification structure in the gravity field,it is found that the solidification structure under electromagnetic stirring is particularly average and the grains are especially small.It is indicated that the solidification structure of Al-5Cu(wt.%)alloy can be improved by electromagnetic stirring to some extent.By comparing the test results under different electromagnetic stirring parameters,it is found that the electromagnetic stirrer in this paper has better stirring effect on Al-5Cu(wt.%)alloy when the working parameter is 100 V and 35 Hz. |
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