Study Of Behaviour Of Particle Group Movement In Elastic Emission Machining

With the development of science and technology, the optical components with uiltra-smooth surface quality, which have become a hot area of research in manufacture industry, have been widely used in high precision products, modern national defense, and other important areas, and will directly influence the precision and surface quality of the products. The technology of EEM studied in this paper has some advantages such as wide processing range, highy machining accuracy, steady material removal and so on, which make it very promising in ultra precision machining of high quality optical components.In this paper, the abrasive grains motion state is simulated and the experimental research of the material removal function is stuied. The theoretical foundation and technical support are provided for the uiltra-smooth surface finishing based on EEM. The main contents are as follows:(1) An EEM experimental platform which has the function of pressure feedback and on-line adjustment is established. The experimental research of EEM of K9glass is carried by using the platform The removal rates are analyzed with different process parameters.(2) The micro flow field in polishing area is calculated by Fluent, the stress condition of the abrasive grains in the flow field is analyzed, the equation of motion of single abrasive grain in the flow field is established, the trajectory of single abrasive grain is simulated respectively using Fluent and Fortran.(3) The collision models of grain-grain, grain-elastic wheel and grain-workpiece are established. Based on the algorithm of Verlet and Fortran, the grain swarm in the flow field is simulated using the collision models.(4) The theoretical EEM removal function in K9glass is established, the removal rate under the condition of different process parameters is simulated.Based on the research above, nano-sized super smooth surface can be obtained by EEM; The simulation model considering the collision of grains can reflect the motion of the grain swarm more objectively; The erosion area is mainly concentrated at the front of the minimum machining gap, there is no impact effect at the minimum machining gap; With the decrease of the minimum machining gap, the impact speed increases and the number of particles impacting the workpiece surface first increases and the decreases; With the increases of concentration of abrasive grain, the number of particles impacting the workpiece surface increases, and the impact speed and impact angle are basically identical; With the increase of the abrasive grain size, the the number of particles impacting the workpiece surface decreases, the impact speed increases, and the impact angle is basically identical; Experimental research and simulation analysis showed that the workpiece removal rate increases with the increases of concentration of abrasive grain and abrasive grain size, decreases with the increases of the minimum machining gap.