Abrasive Pool Photofinishing Technology Based On Gas-Solid Two-Phase Flow And Mechanistic Research

Polishing of parts is an essential process,but the traditional polishing machine processing pressure is large,long time,finishing process also exists in the workpiece surface pits,scratches and other defects of the phenomenon of incomplete removal,seriously shorten the service time of parts.In order to solve this problem,an abrasive pool finishing method based on gas-solid two-phase flow was proposed by analyzing and comparing the surface quality of various finishing methods.The micro-abrasives show fluidization under high pressure gas,and produce high relative motion speed with the workpiece surface,so as to produce highfrequency contact micro-grinding effect on the workpiece surface,and achieve the effect of precision grinding and polishing machining on the workpiece surface.This method has the advantages of high efficiency,low cost,environmental protection and low requirement on workpiece shape,especially for the finishing of curved parts,it has significant technological advantages.In this paper,the abrasive tank equipment designed by ourselves is used to process the workpiece of two different shapes,and the influence of the abrasive tank processing technical parameters on the workpiece surface quality and processing uniformity is studied.Aiming at gas-solid two-phase flow machining technology,the principle and material removal theory of abrasive tank finishing machining are elaborated in this paper,the interaction between abrasive and flow field and abrasive particles is analyzed,and the composition of abrasive tank processing equipment is introduced in detail.On this basis,the different stages of abrasive pool finishing workpiece and material removal process were analyzed by experiments.The surface roughness Ra of workpiece was reduced from 30.0μm to less than 1.0μm.Aiming at the problem that there are many factors affecting the surface quality of abrasive tank machining,the single factor experiment was carried out to determine the four main factors,including air pressure,temperature,abrasive particle size and spindle speed,and select the optimal processing interval of parameters.Orthogonal experiments were designed according to the influencing factors,and the surface roughness and surface topography were used to evaluate the finishing effect of the abrasive pool.The optimal parameter combination was obtained by analyzing the experimental results.After abrasive pool finishing,the workpiece surface roughness can reach 0.352 μm.On this basis,the BP neural network prediction model was established and the reliability of the model was verified.The weights and thresholds of the BP neural network model were adjusted by using the improved chicken colony algorithm(PCSO).The mean square error,root mean square error and regression coefficient were calculated as the evaluation basis.The accuracy and reliability of BP neural network model based on PCSO algorithm are proved.The workpiece surface morphology was observed by scanning electron microscope(SEM),the mechanism of workpiece surface morphology under different parameters was analyzed,and the influencing factors and optimization objectives of abrasive tank processing uniformity were pointed out.Aiming at the problem of poor processing uniformity of the abrasive pool,the processing quality of the abrasive pool under different spindle tilt angles was investigated experimentally.The characteristics distribution of material removal,surface roughness,surface topography,surface microhardness and other parameters on the workpiece surface were used to evaluate the uniformity of the workpiece surface processed by the abrasive pool.The results show that when the spindle Angle is 15°,the material removal amount increases,the surface roughness difference of each measuring point decreases,the workpiece surface machining scratches weaken obviously,the abrasive pool processing effect is more uniform,and the workpiece surface quality is better.At the same time,the surface microhardness of the workpiece after processing in the abrasive tank is also improved.The abrasive pool processing technology proposed in this paper has good finishing performance.Orthogonal experiment was designed on the basis of single factor experiment,and the optimal parameter combination was obtained as air pressure 0.55 MPa,temperature700℃,abrasive mesh 240,spindle speed 1100 rpm,and a reliable prediction model was established to predict the surface roughness.The surface uniformity of workpiece is improved by spindle tilt machining,which provides a basis for the improvement of automatic design of abrasive pond equipment and subsequent research.