| Micro-hole parts have a wide range of applications in aerospace,medical equipment,automotive manufacturing,mold manufacturing and other fields.However,due to the small hole diameter and irregular shape of the micro-hole parts,the conventional polishing technology is difficult to effectively polish the inner surface of the micro-hole parts.The abrasive flow machining technology can be used for finishing the inner surface of micro-hole parts due to its good fluidity and consistency.Therefore,the study of abrasive flow polishing technology provided theoretical guidance and technical support for the development of abrasive flow polishing technology.Based on the discrete element method,the numerical analysis of the micro-holes in the abrasive flow and the related experimental studies are carried out.The CFD-DEM coupling method was used to numerically simulate the micro-holes in the abrasive flow,and the distribution and variation of fluid dynamic pressure,turbulent kinetic energy,velocity,and abrasive velocity,kinetic energy,and total energy were obtained.By discussing the effect of different processing parameters on the wear effect of the wall surface,the law of interaction between the fluid and the abrasive particles is revealed,and the wear mechanism of the abrasive micro-hole wall surface is illuminated.The surface roughness and surface topography of the workpiece before and after polishing were obtained by orthogonal experiments of abrasive flow polishing.The experimental results show that the Ra value of the original surface roughness of the parts can be reduced to 0.196μm after polishing by the abrasive stream from 1.044μm,and the surface quality is obviously improved.Finally,regression modeling is used to establish the mathematical model of surface roughness about processing parameters,which can provide theoretical guidance and technical support for the development of abrasive flow polishing technology. |
