Research On Process Characteristics And Application Of Shear Thickening Polishing

Shear thickening polishing technology is a precision processing method that uses the non-Newtonian characteristics of the polishing medium for polishing.It has the advantages of high polishing efficiency and good polishing quality especially for parts with complex surfaces structure.In recent years,it has attracted the attention of many researchers.Within a given shear rate range,the viscosity of the polishing medium will increase significantly.This dynamic shear thickening effect provides an effective way to improve polishing efficiency and polishing surface quality.In this paper,the shear thickening polishing technology was used to prepare the shear thickening polishing medium.The stability of the polishing medium was improved by adding thixotropic agents and optimizing the distribution ratio of each group;the rheological properties of the polishing medium were tested,which provided data support for simulation and experiment.Through simulation of the flow field of the polishing medium,the influence of different process parameters on the surface pressure of the workpiece was studied,and the experiment was verified by using short rods and high-speed steel taps,which was based on the shear thickening effect of the polishing medium.The main research contents are as follows:(1)Studied the preparation process,media stability and rheological properties of shear thickening polishing media.Stir the polishing medium and added the thixotropic agent to improve the stability of the medium;by optimizing the proportion of each component of the polishing medium,the polishing medium with significant shear thickening effect was obtained;the rheological test of the polishing medium was performed,which provided data support for both simulation and experiment.(2)Simulation study of shear thickening polishing.The influence of different width of the runner,spindle speeds and feed speeds on the pressure of the polishing medium on the surface of the workpiece was investigated.The results showed that with the decrease of the width of the runner,the increase of the speed of the spindle,and the increase of the feed speed,the pressure on the polishing medium on the surface of the workpiece gradually increased.The simulation results provided a reference for the optimization of process parameters in the polishing experiment.(3)Experimental verification of shear thickening polishing through rod polishing.The influence of different type of wall restriction,spindle speed and feed speed on the surface roughness of the rod were studied.The results showed that under the conditions of double wall restraint,higher speed and higher feed speed,the surface roughness of the rod decreased more.After polishing for 20 minutes,the surface roughness of the workpiece could be reduced from about 90 nm to 16.7nm.The new application of shear thickening fluid on cutting edge preparation was verified by tap polishing experiment.The result showed that as the edge preparation time was prolonged,the radius r? gradually increased.After prepared for 300 s,the edge radius could be prepared from 4.28?m to 14.42?m.