Research On Low Viscosity Abrasive Flow Polishing Based On Micro-groove

The polishing research for micro-structure has always a hot research topic in the field of ultra-precision machining,because the fluid is easy to enter the micro-structure surface.The micro-groove low viscosity abrasive flow processing method studied in this paper,which can be well applied to the polishing of micro-structure.The systematic research work has been carried out,including the fundamental principle of micro-groove low viscosity abrasive flow processing,the mechanism of material removal,the polishing platform establishing,the numerical simulation and the polishing experiment.The main research work has been done as follows:(1)The fundamental principle of micro-groove low viscosity abrasive flow processing was introduced.Combined with fluid dynamics theory,the application of turbulence phenomenon to this polishing method was analyzed.The turbulence characteristic is the main factor of material removal,so the turbulence model of abrasive fluid was further analyzed in the flowing process.By introducing the stress state of abrasive particles in the following process,it was analyzed that the disorderly processing of the workpiece could be accomplished by the abrasive particles.Besides,the material removal mechanism was analyzed from the impulsive shear and friction wear aspects.(2)By using the CFD simulation software "Fluent" which is combined with turbulence model,the two-dimensional and three-dimensional simulation optimization calculation was done to the micro-groove low viscosity abrasive flow polishing passage.The distribution of turbulence intensity was analyzed through the simulation.The flow channel was optimized by the analysis of shear force change to workpiece surface and then a better flow channel was acquired.The motion trail of abrasive particles was simulated to further understand the influence of erosion action.(3)The experiment platform for the micro-groove low viscosity abrasive flow processing was built.The flow-limiting device and the tool-head for the form of polishing passage were designed.According to the performance analysis to different abrasives,the SiC abrasive was selected for this experiment.(4)The processing parameters were researched by experimentation.By the polishing experiment for copper,it is concluded that smaller polishing groove depth,larger particle size,bigger polishing pressure and abrasive concentration can obtain better material removal rate.Through the experimental research of stainless steel material,the influence of different processing parameters on the surface roughness of workpiece was analyzed.The experiment results showed that the micro-surface low viscosity abrasive flow processing method can have effective material removal influence on micro-structure workpiece and gain a better surface roughness Ra12nm for workpiece.