| Under harsh working conditions such as high speed and heavy load,parts may suffer overall failure due to local surface damage.As a widely used metal wear-resistant material,Ni20Cr coating has been widely used in machinery manufacturing,petroleum metallurgy,paper industry,and other fields and has received widespread attention.It was found that further incorporation of self-lubricating materials such as Ag and Mo S2into the Ni20Cr coating can reduce the friction coefficient between the coating and the friction pair and improve the wear resistance of the coating.On the other hand,oil monitoring technology can also achieve health monitoring of wear status and wear failure of friction parts.Based on this,the main research content is as follows:Ni20Cr-Ag composite layer with10%Ag content was deposited on 45 steel substrate by subsonic flame spraying technology,and the microstructure and composition of the Ni20Cr-Ag composite coating were analyzed by SEM,XRD,and other methods.Wear tests were conducted using a UMT-5 friction testing machine under dry friction and boundary lubrication conditions to investigate the effect of Ag addition on the tribological behavior of Ni20Cr-Ag composite coatings.Further,Ni20Cr coatings were deposited on Ni20Cr-Ag composite coatings using subsonic flame spraying technology,and the microstructure of Ni20Cr/Ni20Cr-Ag composite coatings was analyzed.At the same time,oil detection technology was used to detect the wear status of the coatings at different times.A Ni20Cr-Mo S2 composite layer with a Mo S2 content of 10%was deposited on a 45 steel substrate by subsonic flame spraying technology.The microstructure and composition of the Ni20Cr-Mo S2 composite coating were analyzed by SEM,XRD,and other methods;Wear tests were conducted using a UMT-5 friction testing machine under dry friction and oil lubrication conditions to investigate the effect of Mo S2 addition on the tribological behavior of Ni20Cr-Mo S2 composite coatings.Subsonic flame spraying technology was used to deposit Ni20Cr coatings on Ni20Cr-Mo S2 composite coatings,and the microstructure of Ni20Cr/Ni20Cr-Mo S2 composite coatings was analyzed.At the same time,oil detection technology was used to detect the wear status of the coatings at different time periods.The tribological properties of Ni20Cr/Ni20Cr-Ag,Ni20Cr/Ni20Cr-Mo S2,Ni20Cr/Ni20Cr-Mo S2/Ni20Cr/Ni20Cr-Ag composite coatings under oil lubrication conditions were analyzed through ball and disk friction and wear experiments.On this basis,the ball and disk friction and wear experiments were combined with oil monitoring technology to analyze the wear status of composite coatings in oil,thereby verifying the application of composite coatings in oil monitoring.The results show that the coating prepared by subsonic flame spraying has fewer micro defects,obvious particle flattening,and good surface quality.The main bonding form between the coating and the substrate is mechanical bonding;In the dry friction state,compared with Ni20Cr coating,Ni20Cr-Ag coating and Ni20Cr-Mo S2 coating have significantly reduced friction coefficient and coating wear volume.The wear type of the coating is mainly abrasive wear accompanied by a small amount of adhesive wear;Under oil lubricated conditions,the tribological properties of the coatings before and after the addition of Ag and Mo S2 were not significantly improved as compared to dry friction,and the three coatings exhibited varying degrees of adhesive wear;Oil monitoring technology can accurately analyze the wear status of multilayer coatings in oil. |
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