Numerical Simulation Analysis And Study Of Electron Beam Orthogonal Deflection Scanning Magnetic Field

Complex parts with high precision are needed in aerospace and biomedical fields.Due to the high thermoforming efficiency and good rapid prototyping precision of electron beam3 D printing technology,it has a good application prospect in the field of additive manufacturing.High-frequency precision scanning control technology is pivotal in electron beam 3D printing equipment,and the deflection scanning magnetic field and control system are the key to the realization of high-frequency precision scanning control technology.In this paper,we study the high frequency precision scanning system of electron beam 3D printing technology,based on the electron beam processing integrated system,the design and development of deflection scanning coil based on electromagnetic field principle and the correction of electron beam deflection aberration,defocus,image dispersion and field curvature,so that the electron beam processing integrated system has the function of high precision of part forming.This paper introduces the current research status of advanced electron beam processing technologies such as electron beam 3D printing,discusses the importance of electron beam deflection magnetic field to achieve precision processing of electron beam,analyzes the principle of electron beam deflection scanning and magnetic field focusing,analyzes the mechanism of electron beam deflection aberration and electron beam focusing error,mainly for electron beam grating aberration,nonlinear aberration,image dispersion and field curvature,and gives a method to correct deflection aberration and focusing error.The results show that the magnetic field of a simple cosine distributed coil is still nonuniform,therefore,the structure of the deflection scanning coil is improved and the distrib uted equivalent cosine structure winding is adopted,which can improve the deflection erro r caused by the grating distortion and improve the uniformity of the deflection magnetic fie ld,and the magnetic field distribution of the deflection scanning coil with different side ten sion angles and the magnetic field distribution of the deflection scanning coil with different diameters is analyzed.The magnetic field distribution of scanning coils with different side tension angles and the magnetic field distribution of different diameters of deflecting scann ing coils are analyzed.The basic principle of the genetic algorithm is introduced,and based on this,the genetic algorithm is improved,and the improved adaptive genetic algorithm pr ogram is written.The total number of turns of the coil in the X-direction and Y-direction of the deflected scanning coil is optimized by using the improved genetic algorithm,and the obtained coil turn values are loaded into the deflected scanning coil model for verification,and the uniformity of the deflected scanning coil magnetic field is improved,and the weak pillow-shaped magnetic field is generated This improves the pillow distortion of the electron beam deflection.The current control strategy for deflection scanning is proposed,i.e.,the establishment of an expert database and a dynamic compensation algorithm,which mainly includes the deflection current parameters at any point of the electron beam deflection scanning area and the focusing current parameters,to dynamically correct the deflection scanning error and the scattering of the electron beam.The experimental observation of scattering and field curvature,and the correction of scattering and field curvature using the proposed deflection scanning coil and dynamic compensation algorithm have been carried out,and the experimental results show that the design of this paper is effective and achieves the accurate control of electron beam deflection position and accuracy.