Study On Thermal Spray Coating Technology And Metallographic Microstructure Analysis Of Aeroengine

After the aero-engine operation reaches a certain life,the thermal component coating will be damaged to some extent,which affects the normal operation of the engine and needs to be repaired by re-spraying the coating.The repair technology of thermal spraying coating for each component is not perfect.The evaluation of coating quality is focused on the analysis of basic physical properties.The coating quality is judged from the aspects of coating mechanical properties,thermal shock properties,hardness and so on.The metallographic structure of the coating was not analyzed.Layer microstructure analysis is one of the most important criteria for coating repair quality.However,there is no specific method for coating microstructure analysis.The most representative coatings(seal coating,metal alloy coating,thermal barrier coating,wear-resistant coating)in the engine accessories were selected as the first choice,and the process of thermal spraying coating was studied.Different kinds of coating powder preparation,spraying experiments and physical and chemical test performance tests have been carried out,and spraying parameters,spraying technology and corresponding spraying materials have been continuously optimized.It is found that the analysis of the metallographic structure of coating is the key to the formation of thermal spraying coating.Therefore,a metallographic structure analysis method should be established for the above-mentioned different coatings.Secondly,by means of three-dimensional digital microscope,scanning electron microscope and other equipment to characterize and analyze coating pores,interface pollution and unmelted particle morphology.The quantitative analysis of coatings is carried out using software(Image-Pro Plus)and microscope image processing technology at home and abroad.The microstructure map of the metallographic coating was established.Finally,Combined with the actual work,through the comparison experiment,the effectiveness of the work done is verified.Based on the research results,through the optimization of process control methods,curing process parameters.A detailed and reliable thermal spraying coating technology and metallographic analysis method have been formed.And built a complete audit system.The research results have improved the thermal spraying coating technology in the repair industry and promoted the development of thermal spraying technology.It is of great significance to guarantee the quality of thermal spraying coating,which is helpful to improve the repair level of Aero engine.