Research On Blade Curved Surface Polishing Technology Based On Flexible Compound Grinding And Polishing System

Polishing,as the final process in blade machining,has important research significance for the final surface quality of the blade and the control of the face shape accuracy.The special structure of the blade and its complex free-form nature pose many difficulties for machining.Secondly,Nickel base superalloy as the most commonly used material for aero-engine blades,low material removal rate and surface quality is difficult to ensure that the difficult processing characteristics have also been restricted to the development of the blade.In this paper,A new flexible compound grinding and polishing tool system is designed for the difficult machining characteristics of blades,combined with the characteristics of flexible machining technology.The feasibility and efficiency of the tool system is verified from both theoretical and experimental perspectives,with regard to both surface quality and removal efficiency.The main researches are as follows.(1)A new flexible compound grinding and polishing tool system is designed from the technical principle of combining existing flexible polishing technology tools.By combining a flexible polishing wheel with a flexible connection structure,the elasticity of the polishing wheel provides a certain degree of passive smoothing of the surface,thus achieving a flexible covering of complex free-form surfaces and avoiding damage to the surface of the workpiece by"hard contact".The rigid abrasive layer used also enables efficient polishing of the blades.(2)For flexible compound grinding and polishing tool system,the material removal mechanism of polishing is theoretically analysed and the reliability of the removal function of the tool system is verified according to the pressure distribution model characteristics.The structural characteristics of flexible composite system are analyzed by static contact mechanics experiment.The effect of process conditions and structural combinations on the removal function is also investigated from an experimental point of view to further investigate the removal capability of flexible composite grinding and polishing tools.(3)The plane grinding and polishing experiment of nickel base superalloy is carried out.Aiming at the surface roughness and material removal rate,the influence law of process parameters and structural characteristics on the grinding and polishing effect is explored,and the feasibility of the system for the processing of nickel base superalloy materials is verified.(4)A blade surface polishing application was carried out.The blade model was reconstructed by reverse scanning,and the CAM function in NX software was used to plan the surface trajectory of the leaf back and generate the corresponding CNC code.The optimum parameters were applied to the blade back polishing and the surface roughness converged from Ra 1.3456μm to Ra 0.0363μm.In a single machining,the surface roughness is reduced by97.3%,and the material removal rate is 0.245 mm~3/min.Through comparison,it is proved that the flexible compound grinding and polishing tool system has great advantages and potential in the machining of complex free-form surface of blade.