Research On Friction And Wear Properties Of UHMWPE Water-lubricated Bearing Materials Modified By Clay With Different Dimensions

Ship stern bearing is a key component of ship power plant,and its friction and wear performance is related to the safety and economy of operating ships.When the ship is in operation,especially in the start-stop phase,low-speed heavy load and speed change and other harsh working conditions,the bearing will face serious friction and wear.The composites prepared by adding self-lubricating and high-modulus clay materials into UHMWPE matrix have been proved to have excellent friction and wear properties,and the dispersion effect of clay materials in UHMWPE will directly determine the reinforcing performance of clay fillers to UHMWPE.In this paper,UHMWPE was used as matrix and attapulgite(3 wt%),modified attapulgite(1,3,5wt%),montmorillonite(3 wt%)and modified montmorillonite(1,3,5 wt%)were used as reinforcement materials respectively to explore the effects of different dimensions of clay and filling content on the friction and wear properties of UHMWPE waterlubricated bearing materials.And draw the following conclusions:(1)The coupling agent KH570 was used to modify ATP and MMT,and the structural changes of the materials before and after treatment were studied.Fourier transform infrared spectroscopy(FTIR)proved that after the material was modified,there were active functional groups of coupling agents on the surface.X-ray diffraction(XRD)method was used to measure that the crystal structure of modified ATP did not change significantly,and the spacing of MMT lamellae increased.The contact angle test showed that the surface polarity of the modified material was reduced,and the binding ability of ATP and MMT particles to UHMWPE was improved.(2)Eight kinds of clay-modified UHMWPE composites were prepared by a combination of solution blending and molding,and pure UHMWPE was set as the experimental control group.The mechanical and physical properties and structure of the samples were characterized and analyzed,and it was found that filling with ATP and MMT could improve the surface hardness of the samples.The tensile properties are gradually enhanced.(3)The friction and wear properties of nine specimens were studied by means of ring-block pair grinding using the SSB-100 testing machine.The friction test shows that: under the same load,the friction coefficient of the sample decreases with the increase of the linear speed;under the same linear speed,the friction coefficient of the sample decreases with the increase of the load.The friction coefficient of the modified ATP/UHMWPE composite was always lower than that of the control sample,and when the modified ATP filling content was 1 wt%,the composite had the lowest friction coefficient.The wear test shows that the modified MMT/UHMWPE composite has better wear resistance than other materials,and when the filling content of the modified MMT is 3 wt%,the volume wear rate of the material is 35.24% lower than that of the pure UHMWPE material.At the same time,the wear surface morphology of the samples was observed,and the friction and wear mechanism of clay/UHMWPE composites with different dimensions was analyzed.