Analysis And Research On Abrasive Flow Machining Process Of Micro-hole

Micro-hole parts are used more and more widely in the aerospace,automotive and other high-precision technology-intensive industries,to ensure the performance of micro-hole parts,the edge or the inner wall of the hole need good surface quality.Traditional polishing technologies have limitations in efficiency and process.However,abrasive flow machining is an ultra-precision fluid polishing process,because the polishing technology is not limited by the parts structure and size,now it has been widely used in polishing micro-holes,narrow and complex cavity and other structures.Based on the analysis of the micro-hole of different parts,the geometrical features of the parts are extracted,and the abrasive flow machining technology in the straight and curved structure of the tiny holes is studied.Firstly,the paper analyze the polishing mechanism of the abrasive flow machining.On this basis,the effects of processing conditions,workpiece properties,abrasive media and fixture on polishing efficiency and surface quality are analyzed.Secondly,using Fluent software to simulate the parameters of the abrasive flow machining process of the straight pipe and the curved pipe.The distribution of pressure,velocity,turbulence kinetic energy and shear stress of the fluid abrasive under different polishing pressure,abrasive viscosity and abrasive concentration are obtained.The result provides a theoretical basis for abrasive flow polishing process.Finally,the polishing experiment of the straight pipe is carried out by using equipment which is developed by laboratory.The influence of the polishing pressure,the processing time,the abrasive concentration and the grain size on the surface roughness is obtained,and P=8MPa,T=120min,D=38?m,C=40% is the best parameter combination,can make the straight pipe wall surface roughness from 0.983?m to 0.156?m.The results obtained in this paper can provide reference for polishing process parameters when using abrasive flow machining to polish mirco-hole parts,and also provide technical support for the application and development for abrasive flow machining technology.