| Electrochemical finishing is an advanced technology which uses the principle of anodic dissolution to level the surface of anode workpiece.Although electrochemical finishing technology has been widely used in the surface finishing of key parts in recent years,it has encountered bottlenecks in the processing of parts with complex structure and higher surface quality,such as aerospace vehicles,spiral bevel gears and so on.Therefore,how to further improve the surface quality of parts,improve the localization of finishing and machining efficiency has become a key problem.In this paper,the external magnetic field is used to solve the above key problems.In order to reveal the research mechanism of magnetic field on electrochemical finishing,this paper introduces the leveling mechanism of magnetic field electrochemical finishing,and builds the experimental platform of magnetic field electrochemical finishing and The influence of magnetic field on flow field in electrochemical finishing gap was simulated by COMSOL Multiphysics.Finally,a reasonable experimental scheme is designed to discuss the influence of magnetic field on the efficiency of electrochemical finishing,the surface quality of parts and the localization of finishing.The simulation model of magnetic field changing the flow field in machining gap is designed by COMSOL Multiphysics simulation software.The results show that: in static fluid,when the magnetic field is perpendicular to the electric field and parallel to the flow field,it can drive the fluid at the place with strong electromagnetic force,and hinder the fluid at the place with weak electromagnetic force,and two annular flow coils are formed in the flow field of machining gap;when the magnetic field is separated from the electric field and the flow field,the magnetic field can drive the fluid When the machining gap is not vertical,two annular flow coils are formed.Both of them stir the electrolyte in the machining gap and reduce the concentration polarization.When the magnetic field is perpendicular to the electric field and parallel to the flow field,the influence of the electromagnetic force on the flow field is the largest.When the magnetic field is perpendicular to the electric field and the flow field,the influence of the electromagnetic force on the flow field is the second.When the magnetic field is parallel to the electric field and perpendicular to the flow field,the influence of the electromagnetic force on the flow field is the smallest.In the experiment of the effect of magnetic field on the efficiency and micro morphology of electrochemical finishing,it is concluded that the processing efficiency is not improved,but will be inhibited under the condition of low flow rate and small magnetic field,but the processing efficiency is gradually improved with the increase of magnetic field and flow rate.On the whole,the machining efficiency is the highest when the magnetic field is perpendicular to the electric field and the flow field respectively,and the lowest when the magnetic field is parallel to the electric field and perpendicular to the flow field.After magnetic field electrochemical finishing,the surface roughness is high and the surface quality is better.The experiment of the effect of electro-optical finishing on the localization is designed.The quality of the localization is judged by comparing the degree of stray corrosion on the surface of the parts during the process of the surface of the hole.The results show that the magnetic field perpendicular to the direction of superposition and electric field is 42.7% higher than that of non superposition magnetic field,and 22.6%higher than that of the superposition of parallel electric field.Therefore,the addition of magnetic field perpendicular to the electric field can effectively improve the local solubility of electrochemical anode and improve the localization of electrochemical finishing. |
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