Numerical Simulation On The Flow Field Of Electromagnetic Stirring Of Semi-solid Slurry Of Aluminum Alloy And Experimental Research

The quality of semi-solid slurry has correlation with the parameter of the electromagnetic stirring.As the purpose of this research,the kinetic characteristic and rule of the fluid during the process of electromagnetic stirring of semi-solid slurry of aluminum alloy will be obtained through the simulation of flow field with computer. The optimized processing parameters of electromagnetic stirring will be found with the experimental research.Firstly,the modeling and simulation of the coupling of the electromagnetic field and the flow field of electromagnetic stirring were done with the software ANSYS. And then the distribution of the magnetic lines of flux,the magnetic flux density of the magnetic field,the value of Lorentz force of the aluminum alloy melt were obtained through the numerical simulation of the electromagnetic field.We can find two equal swirls distributed in the melting area lengthways from the result of the simulation of the flow field.And the result accorded with the principle of the electromagnetic stirring.The maximal flowing velocity of the inner melt presents to the top right corner and the bottom right corner of the melting area.The minimal flowing velocity of the inner melt presents to the central area of the swirls.The elementary alteration rule of the maximal flowing velocity and shearing rate of the inner melt have been analyzed through the numerical simulation with the separately alteration of stirring frequency,current density,ratio of height and diameter of aluminum melt and stirring temperature.We get the rule and the sequence of the primary and secondary of the influence of the four factor including stirring frequency,current density,ratio of height and diameter of aluminum melt and stirring temperature to the maximal flowing velocity of the inner melt,through designing the orthogonal numerical experiment.The programme of the experiment has been drawn up.Observing and comparing the microstructure of the test samples which were got from different stirring power(1.8 kw/kg,1.2 kw/kg,0.8 kw/kg,0.6 kw/kg ) under different temperature(600℃,595℃,590℃).We can find the microstructures of test samples are optimal under the same stirring power when the temperature is 595℃.So 595℃is a proper temperature at which we can stop the electromagnetic stirring.Observing and comparing the microstructure of the test samples which were got from the same temperature(595℃) under different stirring power(1.8 kw/kg,1.2 kw/kg,0.8 kw/kg,0.6kw/kg).We can find all of the primaryα-Al grains are not fir-tree crystal but near-spherical and rose-shaped.The primaryα-Al grains are the best-distributed,the smallest and roundest when the stirring power is 1.8 kw/kg.From the result of the experiment we know that the velocity of the fluid is the main factor which influence the ultimate microstructure of the semi-solid slurry.The higher the velocity of the fluid become,the better the effect of the electromagnetic stirring will be.We can get primaryα-Al grains which are better-distributed,smaller and rounder more easily.Conversely,the lower the velocity of the fluid become,the worse the effect of the electromagnetic stirring will be.So,the conclusion of the numerical simulation on the flow field of electromagnetic stirring of semi-solid slurry of aluminum alloy is a meaning of positive guidance to the experimental research to a certain degree.