Study On Kinematic Law And Processing Test Of Gas-Liquid-Solid Three-Phase Polishing Abrasive

Gas-liquid-solid three-phase abrasive flow machining method utilize the cavitation impact produced by the collapse of the micro-bubble to drive abrasive polishing workpiece surface,which not only increasing the polishing efficiency,but also reducing the sub-surface damage.At present,the research focus of this method is mainly focused on the control of the boundary condition of abrasive grains,such as the angle of incidence and the incident speed of the abrasive grains.However,the kinetics law of the abrasive grains in the flow field are not deeply excavated and directly measuring.It is great significance on forming cavitation impact abrasive controllability and improving the polishing efficiency by studying on kinetics law of cavitation impact abrasive grains in the near-wall flow field of gas-liquid-solid three-phase abrasive grains.In this paper,the three-phase abrasive grains are described mathematically by the modified turbulence model.The polishing flow field is measured by PIV technique.The micro-bubble compensated gas-liquid-solid three-phase abrasive grain polishing method is proposed and processed.Based on this,the main work of this paper is as follows:(1)Taking the polishing technology of large plane electronic information material as the research background,and discussed the advantages and disadvantages of the existing processing methods.A review of domestic and foreign related research is put forward,and a gas-liquid-solid three-phase abrasive grain polishing method is proposed.This paper focuses on the theory and technology involved in this method,and determines the main research contents and post-sequence tasks.(2)Analyzing the three-phase flow field characteristics base on the realizable k-?turbulence model and modifying the theoretical model.Combining with the Mixture model,the mathematical description of the gas-liquid-solid three-phase abrasive grain flow field is more accurate.Studying on kinetics law of the cavitation impact abrasive grains in the near-wall and analyzing the force of the single abrasive grain in the flow field(3)The geometrical model is established and the parameters are set and the numerical simulation is carried out after comprehensive analysis of gas-liquid-solid three-phase abrasive flow field characteristics.Base on simulation results,analyzing the three-phase abrasive flow field characteristics and the cavitation abrasive movement law in different polishing models.So as to select the best entry number of polishing tools and set micro-bubble compensation to improve the polishing model in the flow field that low turbulent kinetic energy and dynamic pressure.A microbubble compensated gas-liquid-solid three-phase abrasive grain polishing method was proposed.(4)PIV system can measure the motion pattern of flow field without interfering,which is helpful to analyze the dynamic law of the three-phase abrasive grain flow.Design of gasliquid-solid three-phase abrasive grain PIV measurement test platform and observe the flow field formed by the four inlet polishing discs.The velocity vector and vorticity are calculated by image processing algorithm.The accuracy of numerical simulation and the feasibility of finishing method was verified in this way.(5)Designing and building gas-liquid-solid three-phase abrasive flow micro-bubble automatic adjustment processing test platform and polishing workpiece.After 4h polishing,the maximum roughness of the silicon wafer in the B region decreased from 10.4?m to 1.3?m and the average roughness reached 0.7?m,and there was no trace of processing.The results show that the results of numerical simulation and PIV measurement are consistent with the actual processing results.The effectiveness of gas-liquid-solid three-phase abrasive-flow micro-bubble compensation machining method is proved.