Mechanism And Experimental Research On Micro-hole Abrasive Flow Polishing

With the rapid development of modern technology,people have higher requirement for mechanical products.Especially light-duty miniaturization,precision machinery parts become increasingly widespread.In the space,mobile phone,automobile manufacturing and other industries,more and more complex structure parts have been applied.After parts are manufactured,they need to be polished and deburred.But traditional polishing technology has some disadvantages,it is difficult to meet the process requirements now.And polishing abrasive flow processing technology can meet the requirements of present processing technology,especially suitable for complex curved surface shape,complex pore structure,crossing hole inner cavity and microscopic pore structure parts.At first,this paper studies on the development of abrasive flow polishing technology at domestic and overseas.Combined with domestic and overseas development present situation,putting forward a set of abrasive flow polishing device design scheme.The device’s advantages are simple to operate,easy to clean and the cost is far lower than the market price at domestic and overseas.Through the study of mechanism of abrasive flow polishing,talking about the mechanical properties of abrasive in the micro-hole and the pressure distribution law and velocity distribution law in the micro-hole.Then on the basis of these theories,fluid simulation analysis of abrasive in the movement was carried out in the micro-hole.According to the structure characteristics of the nozzle,the mathematical equation of abrasive flow are established. Meshing the structure of micro-hole in the software Gambit. According to the theoretical analysis,choosing turbulence model and the boundary conditions that are suitable for abrasive flow movement characteristics.Two-dimensional simulation of micro-hole are carried out through the fluid simulation software Fluent,and simulating abrasive movement state in the nozzle.By defining the import and export pressure,can simulate abrasive pressure distribution,velocity distribution,voltage regulator turbulent kinetic energy distribution,voltage turbulence viscosity distribution parameters and so on. And it’s the basis for polishing device research and experimental study.On the basis of theoretical research and simulation analysis,designed an abrasive flow polishing equipment.In view of the nozzle structure and technological requirements,complet-ing to design the hydraulic cylinder,abrasive cylinder,nozzle clamp,pipeline,supports and some auxiliary parts,and to select pipe joint,seals and other parts reasonably.The experiment proves that the design of abrasive flow polishing equipment is reasonable,and it can reach the requirement of the enterprise.Finally using the configure abrasive to polish the micro-hole and analyzing the influence law of three kinds of parameters of abrasive concentration,supply pressure,processing time on the micro-hole polishing effect.Using spiral micrometer to test polishing effect in the nozzle inner surface,and observing the influence law of three kinds of parameters on the polishing effect.The polished nozzle is installed in the pneumatic injection valve,and testing nozzle polishing effect further.Finally getting the optimum polishing parameters of micro-hole through the experiment.