| Steel is a kind of soft magnetic material,which is widely used in the majority of fields,it can be used as the high-frequency transformer,the pulse transformer,the pulse generator,the high-power magnetic amplifier,the storage,the memory element and the magnetic shielding.But the more frequency,the worse loss.To decrease the energy loss when using this material and to study how the doman influence the magnetic properties,it is very important to research the dynamic magnetization process.Besides,it is still a puzzle about the self-magnetization in terms of steel,and it is also a problem the how the magnetic moment and magnetic domain change in the alternating current field,which cannot set up the strong basic theory.To boost the soft magnetic property of Fe-Si material,it is an urgency to study the ground state in the self-magnetization process and the model of steel' magnetic domain in the microcosmic scale.Now it is popular to research magnetic domain by micro magnetic simulation,which is partly because micro magnetic simulation can definitely figure out the structure of magnetic domain,the inversion of magnetic moment,the displacement of domain wall and so on by simulating the evolution of magnetic moment distribution without setting a valid domain.Moreover,the traditional macro magnetism performance curve and parameters can be obtained easily such as magnetization curve,hysteresis loop,permeability and ?Q,which is vital to rebuild the knowledge of these macro properties that are obtained from analysis of the microscopic mechanism.This paper aims to figure out the transformation rule of magnetic moment of Fe-3%Si steel in the process of self-magnetization and dynamic magnetization,then to explore the ground state among the different dimensions.And these conclusions can be used to guide the practical production and the practical application of the silicon steel.The materials are Fe-3%Si steel.It utilizes the micro magnetism principle and L-L-G equation to perform numerical calculation simulation.What is more,it also researches the alteration of permeability in term of different frequencies,domain structures and rotation of magnetic moment.As for the specific fields the paper researches,they are listed as follows:(1)It introduces briefly the micro magnetism principle and the model of Landau-Lifshitz-Gilbert(L-L-G)equation,The method of Runge-Kutta is used to figure out the LLG equation.It also designs an algorithm process about time step control of the dynamic ac magnetization system,which builds the foundation for the simulation's calculation,analysis and discussion.(2)It studies the self-magnetization process which is from the demagnetization state to the ground state in terms of the three different dimensions steels.Then the steadiest ground state can be obtained.In this process,the exchange field and the demagnetizing field force the rotation of magnetic moments and the formation of magnetic domain.It also finds an interesting phenomenon that there are some declining steps in the change of exchange energy,which is relating the vertical annihilation.Finally it concludes the relation between the total energy and the dimension.(3)The Fe-3%Si steel can still possess the better soft magnetic properties in the frequencies between 10MHz to 100MHz.And there is a relaxation phenomenon in the ac field in terms of the magnetization.Then the phenomenon of magnetic dispersion can also be observed based on the magnetic spectrum in the ac field and it is caused by the domain wall resonance and the domain natural resonance.Finally,the better dimension,which has better soft magnetic properties,can be obtained.(4)It studies three special stages when the Fe-3%Si steel is in the ac field:initial magnetization stage,residual magnetism and coercive force stage.And there are many flexible relations between the magnetic domain and the change of all kinds of energies.Then the magnetic moments can rotate in the way of precession,when they are forcing by the ac field. |
PDF Full Text Request