Study On Dynamic Accumulation Process Of Magnetic Abrasive Particles In Magnetic Induction Free Abrasive Wire Sawing

In traditional free abrasive wire sawing process,the abrasive particles are often difficult to be transported into the long and narrow slot zone,thus leading to the wire sawing performance deteriorated,such as poor surface quality,high kerf loss,and low cutting efficiency,etc.These problems are more prominent when slicing large size of the silicon crystal.In order to transport more abrasive particles into the cutting zone,a novel method named as magnetic induction-free abrasive wire sawing is proposed.It is a hybrid process that introduces a uniform magnetic field into traditional free abrasive wire sawing technology.A ferromagnetic saw wire is magnetized by the external uniform magnetic field,and then it generates a high gradient magnetic field around itself.Magnetic abrasive particles are attracted to the surface of the wire by the magnetic force,which leads to more abrasive particles carried into the sawing channel.This novel method effectively improves the utilizing rate of abrasive particles and is helpful to improve the wire sawing performance.Based on the research of magnetic induction free abrasive particle wire sawing,the accumulation of magnetic abrasive particles on the surface of the saw wire in the being about to go into the cutting area was studied theoretically and experimentally.The dynamic accumulation process of magnetic abrasive particles on the surface of the saw wire in high gradient magnetic field was simulated and analyzed.After high gradient magnetic field is generated,the influence of magnetic abrasive packing on high gradient magnetic field and the influence of high gradient magnetic field on the shape of magnetic abrasive packing are studied.The main research contents are as follows:(1)The influence of the direction of the magnetic field on the dynamic characteristics of the magnetic abrasive particles in the being about to go into the cutting area was simulated and verified by the experimental platform.The results showed that as the direction of the magnetic field changes,the magnetic abrasive particles are only adsorbed on both sides of the wire parallel to the direction of the magnetic field,and on both sides of the wire perpendicular to the direction of the magnetic field,the magnetic abrasive particles are not adsorbed by the repulsive force.(2)The effect of the accumulation of magnetic abrasive particles on the surface of the wire on the high gradient magnetic field around the wire is simulated.With the accumulation of magnetic abrasive particles on the surface of the wire,the accumulated magnetic particles will be magnetized by the external magnetic field and superimposed with the original magnetic field.The high gradient magnetic field around the wire is weakened,and the change of the high gradient magnetic field affects the stacked shape of the magnetic abrasive particles.(3)The orthogonal test method was used to simulate and analyze the influence of magnetic field strength other factors on the adsorption rate of magnetic abrasive particles,Further analysis was carried out by setting up the experimental platform.The results showed that the adsorption rate of magnetic abrasive particles increased with the addition of uniform magnetic field strength,the reduction of the cutting fluid dynamic viscosity,the increase of the speed of slurry supply,and the increase of the magnetic abrasive particle size,combined with simulation and experiment,the optimal horizontal combination is obtained.Through the research,the following conclusions are drawn:as the direction of the magnetic field changes,the magnetic abrasive particles are only adsorbed on both sides of the wire parallel to the direction of the magnetic field;the accumulation of magnetic abrasive particles weakens the high gradient magnetic field around the wire,and the change of the magnetic field will affect the accumulation of magnetic abrasive particles on the surface of the wire;the orthogonal test shows that the optimal horizontal group is the magnetic field strength of12.7×10~5A/m,the speed of slurry supply is 12mm/s,the cutting fluid dynamic viscosity is0.0047 Pa·s,and the magnetic abrasive particle size of 25μm.It is innovative to study the interaction between magnetic abrasive particles accumulation and high gradient magnetic field.However,this paper mainly deals with the study of magnetic abrasive particles in the being about to go into the cutting area,The law of cutting area needs further study.