Research And Optimization Of Tribological Properties Of Composite Wear-Resistant Coating

Aiming at the serious wear problem of the side plate and bearing of the fuel pump of an aero-engine under the condition of high speed and high temperature,the solid lubrication coating was prepared to extend the service life of the component,and the tribological performance of the solid lubrication coating was tested.Based on the existing problems of the coating,the performance of the coating was improved from two aspects of coating formulation and preparation process,and finally a new composite wear-resistant coating with more excellent anti-wear performance was obtained.First,the composite wear-resistant coating was prepared by the bonding method,and the tribological performance of the composite wear-resistant coating in RP-3 aviation kerosene was tested on the MFT-5000 ball-disk friction and wear tester.The effects of different rotation speeds,different loads,and different wear on the tribological properties of the coating were studied separately.The wear scars of the coating were characterized by means of three-dimensional profilometer,scanning electron microscope（SEM）,X-ray energy spectrometer（EDS）,To explore the wear mechanism of the coating in RP-3aviation kerosene.The results show that the wear process of the coating in RP-3 aviation kerosene is mainly divided into three stages:running-in stage,stable wear stage,and failure stage.The main failure modes are abrasive wear and slight adhesive wear.In addition,kerosene pollution experiments show that kerosene pollutants have little effect on the tribological properties of the coating.However,during the research,it was found that the coating was relatively severely worn on the surface of the abrasive parts,and the contact area contained a large amount of hard particles.Then,the preparation process of the coating was optimized.The results showed that when the blasting mesh number of the coating was 150 mesh and the stirring time exceeded 6h the coating had the best tribological performance.In addition,polishing which reduces the surface roughness of the coating,reduce effectively the wear of the coating andthe mating specimen.Finally,the coating formulation was improved by replacing or reducing the metal oxide content and adding MSH,as well asby improving the dispersion of the solute.The results showed that the addition of MSH effectively improved the friction and wear properties of the coating.When the filler mass ratio of the coating waas Al₂O₃:Ce F₃:MSH=2:1:1,the tribological properties of the coating were the best.After that,the surface roughness,adhesion and other parameters of the improved coating were tested.The results show that all parameters meet the requirements of the project.