Research And Optimization Of Grinding And Polishing Process For Aeroengine Blades

Blade is one of the most important parts of aeroengine.Its machining quality directly determines the performance and service life of aeroengine.In order to meet the severe environmental requirements of the engine,there are special requirements for the structural shape design and material selection of the blade.The structural and material characteristics of the blade increase the difficulty of blade processing.At present,the processing and manufacturing level of Aeroengine Blades in China is relatively backward,and its processing efficiency and quality can not meet the needs of China's aviation industry.However,major foreign research institutions and companies have blocked the manufacturing technology of Aeroengine Blades.Therefore,it is of great significance for China's aviation industry to study and analyze the machining process of Aeroengine Blades and improve the machining quality and efficiency.Because the surface quality of Aeroengine Blades has a direct impact on the working performance and service life of the engine.In this paper,the blade grinding and polishing experiment platform is designed and built independently.The grinding and polishing technology of Aeroengine Blades is studied and optimized.Firstly,the machining difficulties of blades are analyzed,and the grinding and polishing mechanism is studied and analyzed according to the selected grinding and polishing tools.Secondly,the theoretical model and experimental analysis of the contact force and the characteristics of the contact area are carried out.Furthermore,the distribution of positive pressure in contact area and the model of material removal rate are obtained.Finally,the grinding and polishing experiment is carried out.Based on the experimental data and Kriging theory,the agent model is established.And the optimal combination of machining parameters is obtained by optimizing the grinding parameters under the genetic algorithm.The main contents and achievements of this paper are as follows:(1)Through the experimental research and analysis,it is determined that the tool selected in the grinding process of Aeroengine Blades is forged brown corundum sand belt.Firstly,based on the structure and material characteristics of the blade,the problems and difficulties in the processing of the blade are analyzed,and the appropriate grinding and polishing tools are determined.Then,the wear,removal rate and grinding heat of different belt materials are analyzed.According to the experimental results,the appropriate belt material is forged brown corundum.(2)Based on Preston equation,the material removal rate model of aeroengine blade grinding and polishing process is established.The grinding and polishing contact force of the blade grinding process was researched and analyzed according to the belt grinding mechanism..First of all,under the same condition,the error of contact force in static state and moving state is analyzed.Considering the large error caused by external environment factors,choose the contact force in dynamic state to establish the functional relationship between contact force and downforce.Secondly,single factor experiment was used to study the influence of different factors on the contact area.Finally,according to the conclusion of contact force and contact area characteristics,the distribution law of positive contact pressure is analyzed and the material removal rate model is established based on Preston equation.(3)Based on Kriging theory and orthogonal experimental data,the grinding and polishing agent model is established,and the optimal machining parameters combination is obtained by NSGA-? intelligent optimization algorithm.Firstly,the material removal rate and surface roughness are determined as the processing quality evaluation parameters in the process of blade grinding and polishing,and the tool and process parameters of grinding and polishing experiment are determined.Secondly,the influence range of different parameters is determined by single factor experiment analysis,and then the optimization parameters are determined by orthogonal experiment.Finally,based on the data of orthogonal experiment,the grinding and polishing agent model is established,and the optimal parameter combination under the double objectives of material removal rate and surface roughness is obtained by NSGA-? intelligent optimization algorithm.(4)The experimental platform of blade grinding and polishing was built and the validity of the optimized machining parameters was verified.First of all,considering the processing requirements and the current situation of the laboratory processing environment,the machining tools are designed,and the blade grinding and polishing experiment platform is built.Secondly,on the experimental platform,the machining effect of the optimized combination of grinding and polishing parameters and the combination of grinding and polishing parameters obtained by experience are compared,and the effectiveness of the optimized combination is verified,which greatly improves the machining efficiency under the premise of ensuring the surface quality..