Research On Precision Magnetic Particle Grinding Technology For Inner Surface Of Pipe Fittings Based On Low Frequency Alternating Magnetic Field

Electromagnetic magnetic particle grinding process is a kind of magnetic particle grinding process,is the use of the magnetic field generated by the current coil to polymerize magnetic abrasive particles,produce a certain rigid "magnetic particle brush",with the relative movement of the workpiece,the surface of the workpiece for sliding,so as to achieve the surface of the workpiece finish processing of special processing technology.Magnetic particle grinding technology has good flexibility and adaptability,which can be used to grind the surface or cavity of parts of various shapes.Compared with traditional grinding or permanent magnetic particle grinding,electromagnetic magnetic particle grinding has some advantages,such as easy control of magnetic field direction and adjustable magnetic field strength.Although electromagnetic magnetic particle grinding technology has been used in finishing,it is not widely used in practice because of its complexity,limitations and the diversity of processed parts,and most of the processing parameters are determined according to the processing experience.Therefore,it is necessary to carry out further analysis and research on the design and grinding mechanism of the electromagnetic magnetic particle grinding device,and optimize the process parameters of the specific experiment,and get the process parameters with high processing efficiency and good effect.In this paper,based on the design of electromagnetic magnetic particle grinding equipment for processing device,and at the completion of a specific experiment,on the basis of analysis of experimental data processing,the grinding mechanism of electromagnetic magnetic particle grinding process for discussion and analysis,and applied research on ceramic pipe as an example,using the response surface method to design the Box-Behnken experiment to optimize the process parameters.The specific content includes the following aspects:(1)A magnetic particle grinding and polishing device was designed based on the low frequency alternating magnetic field.The magnetic particle grinding processing method was used to finish the inner surface of pipe fittings by using the electromagnetic excitation method to form controllable low frequency alternating magnetic field.(2)The generation mode of electromagnetic field was analyzed,and the magnetic field lines around the device were simulated by COMSOL Multiphysics Coupling Analysis software.Secondly,the electromagnetic field changes in the processing area were simulated by ANSYS Maxwell software.The distribution and movement rule of magnetic abrasive in electromagnetic field were revealed,the force of single magnetic abrasive was analyzed according to the simulation results,the self-sharpening phenomenon of magnetic abrasive was explained from the perspective of the abrasive movement and mutual friction,and the cutting mechanism of magnetic mixed abrasive was revealed.(3)Taking the ceramic pipe of a military enterprise as the research object,various factors affecting the effect of magnetic particle grinding were analyzed,including the current frequency,iron particle size,diamond particle size and pipe fitting speed,etc.,and the relationship between the magnetic mixed abrasive particles and the relative motion of pipe fitting and the distribution of low-frequency alternating magnetic field was further studied.The Box-Behnken experiment was designed by response surface analysis to optimize the process parameters under a single performance index(surface roughness Ra),and verified by experiments.Finally,the optimal process parameters were obtained under this working condition.