Study On The Properties Of Composite Ceramics And Coating Materials Facing To The Key Frictional Associated With Sea Water

In recent years,the development of marine equipment has been listed as a key research area.The common materials such as metals can not meet the performance requirements of marine equipment.However,composite ceramics have excellent corrosion resistance and high temperature resistance,which can better replace the existing key parts.Based on,In order to expand the application of key friction pairs in the Marine environment.The mechanism of the tribological properties of the above three pairs was studied when the three parameters of variable load,variable speed and variable content?h BN content?were changed.The aim is to investigate the effect of three variables on the tribological properties of the three friction pairs of Si₃N₄-h BN/2507,Si₃N₄-h BN/PEEK,and Si₃N₄-h BN/2507-basedPEEKcompositecoatingsinseawater environments.The analysis methods of SEM,EDS and XPS were used to analyze the changes before and after the friction surface test.The main work of this article is as follows:?1?The performance change of Si₃N₄-h BN/2507 friction pair under variable load conditions in seawater medium were discussed.The results show that the friction coefficient between the Si₃N₄-h BN and the 2507steel at the 20N parameter is as low as 0.38,and the wear rate of the pin and disc of the matched pair is as low as 10^-55 orders of magnitude.The main wear mechanism of the friction pair is abrasive wear and corrosion wear.On the other hand,the friction factor and the wear rate change more obviously with the change of speed,With the increase of the grinding range,the friction coefficient of the friction pair is minimum when the speed is1.73 m/s.In particular,the friction coefficient of the SN20 at 1.73 m/s is as low as 0.38.Under this parameter,the wear rate of the pin plate is also in the order of 10^-5.?2?The effect of variable load speed on the tribological performance of Si₃N₄-h BN/PEEK friction pair under seawater environment was compared.The results show that the change of the load can significantly reduce the friction coefficient and wear rate of the friction pair.The friction coefficient of the SN20 friction pair is as low as 0.07,the wear mechanism is mainly adhesive wear and corrosion wear.When the load is fixed at 20N,the friction coefficient of the Si₃N₄-h BN/PEEK pair is low overall,and the tribological performance is better at a speed of 1.73m/s,where the friction coefficient is as low as 0.07.The wear mechanisms are mainly adhesive wear and abrasive wear.?3?Based on the above studies,the tribological properties of Si₃N₄/2507-based PEEK composite coatings under constant load?20N?and constant velocity?1.73m/s?were investigated again.As a result,it was found that the friction coefficient of the friction pair rose significantly with the increase of h BN.The friction coefficient of the 2507 metal-based PEEK coating of SN0 and 0%h BN was as low as 0.05.The friction coefficient of the 2507 metal-based PEEK coating with SN0 and 3%h BN increased to 0.57.When the content of h BN in the coating is further increased by 6%,the friction coefficient rises significantly to 0.12,and the wear rate under this parameter is also high.This is due to the addition of different amounts of h BN to increase the porosity of the coating material,reduce the degree of bonding between the coating and the metal matrix,and accelerate the corrosion of seawater.The study shows that in the seawater environment,the friction pair of Si₃N₄-h BN/2507metal friction pair,Si₃N₄-h BN/PEEK,Si₃N₄-h BN/2507metal-based PEEK composite coating has better service performance under specific parameters.This not only provides theoretical support for the development and application of marine engineering equipment,but also provides new ideas for the selection of key friction pairs in marine equipment to a certain extent,and has important engineering application value.