Basic Problems And Experimental Research On Robotic Grinding And Polishing Of Superalloy Blade

Aeroengine is like the "heart" of aircraft,known as the "pearl in the industrial crown",which is one of the important symbols of a country’s comprehensive strength.The key to improve its performance is to improve the performance of turbine blades.The working environment of turbine blade is very bad,and most of them are made of superalloy.Due to the functional requirements,the blade to be processed area has different degrees of curvature,the traditional consolidated abrasive tool is not suitable for processing this"special-shaped parts",while the abrasive belt grinding and polishing method is known as"universal grinding and polishing",and its auxiliary equipment has certain flexibility,which is suitable for processing complex surface parts.With the continuous development of abrasive belt technology,the abrasive belt grinding and polishing of blade is gradually changed from manual operation to automatic production of CNC machine tools,and robot abrasive belt grinding and polishing technology emerges as the times require.Robot abrasive belt grinding and polishing as a new and gradually developed processing method,its processing basic problems and experimental research need to be improved.In this paper,the surface quality and material removal of nickel base superalloy GH4169 parts by robot abrasive belt grinding and polishing,as well as the wear and trajectory lapping of accumulated abrasive belt are studied based on experimental research,supplemented by finite element simulation and theoretical analysis.The main research contents are as follows:(1)Research on surface quality of nickel base superalloy parts machined by robot belt grinding and polishing.Firstly,the single factor experiment was designed and carried out to explore the influence of process parameters on the surface roughness and surface morphology of nickel base superalloy workpiece.Then,the primary and secondary order of the significant degree of process parameters on the surface roughness was obtained through orthogonal experiment,and the optimized process parameter combination within the parameter range was obtained,and the reasonable suggestions on the selection of process parameters were put forward,Finally,the surface roughness prediction model of robot abrasive belt grinding workpiece is established,and the accuracy of the model is verified.(2)Research on material removal in robot belt grinding and polishing of nickel base superalloy parts.Through theoretical analysis and single factor experiment,the approximate functional relationship between material removal depth and process parameters was obtained,and the debris morphology was observed and analyzed to understand the material removal mechanism.According to the results of single factor experiment,the mathematical model of material removal was established.The order of the significant degree of the process parameters on the material removal depth was obtained through orthogonal experiment.The reasonable suggestions on the selection of process parameters were put forward,and the empirical formula of quantitative removal of nickel base superalloy machine abrasive belt within the selected parameters was obtained.The superalloy material can be removed accurately and quickly by flexible grinding and polishing.(3)Research on abrasive belt wear and trajectory overlap rate.The wear characteristics of pyramidal and solid abrasive belts were studied by experiments.By recording the abrasive belt wear amount and material removal depth,the change curve of abrasive belt wear height and material removal depth with time was obtained,and the stable period of abrasive belt processing was found out.Through the observation of wear particle morphology in different wear stages,the characteristics of each stage in the wear process of the two kinds of abrasive belts are understood,and the advantages and disadvantages of the two kinds of abrasive belts are mastered.Based on the theoretical analysis of the track overlap problem,the calculation formula of the track number is derived.Combined with the experimental results,some suggestions are put forward for the selection of the track overlap rate.(4)Simulation study on material removal process of nickel base superalloy.The ABAQUS software was used to simulate the material removal process of a single abrasive grain cutting nickel-based superalloy GH4169.The temperature field and stress field distribution characteristics were summarized,and the influence of process parameters on the grinding temperature was obtained.The trajectory equation of all abrasive particles on the surface of the abrasive belt is derived,and the surface morphology of the abrasive belt is simulated by Matlab software,and the surface roughness value is roughly calculated.(5)Robot abrasive belt grinding and polishing of superalloy blade.Combined with the previous experimental results,the reasonable abrasive belt grinding and polishing method and trajectory planning method were adopted to grind and polish the superalloy blade.The surface morphology of the blade before and after processing was observed,and the grinding and polishing of the blade surface was preliminarily realized.The feasibility of using the current equipment and processing method to realize the blade surface processing was verified.