Research And Predict Of Tribological Properties Of PTFE Matrix Composites In Freshwater Environment

With the continuous development of materials science,economical,practical,green and environmentally friendly new materials have gradually become research hotspots in the field of tribology.In some complex working environments?high temperature,dust,etc.?,traditional grease lubrication can no longer meet the requirements of industrial production,so solid self-lubricating materials are needed to reduce the impact of friction and wear.China has a vast territory and abundant freshwater resources,and the particularity of freshwater itself has greatly restricted the exploitation of resources.Therefore,it is of great significance to study self-lubricating materials with excellent tribological properties in freshwater environments.The project uses polytetrafluoroethylene?PTFE?as the matrix,nano-La₂O₃ and nano-serpentine as additives to prepare composite materials.The uniform design test method is selected,and the ratio of the two additives is defined as the influencing factor of the test.Measure the water absorption and hardness of composites at different levels,analyze the effect of additive mass fraction on the water absorption and some mechanical properties of the material,and provide assistance for the study of tribological properties.Self-made freshwater environment simulation device,design and carry out freshwater environment tribology test.Combining curve fitting and multiple regression to predict the theoretically optimal solution for the tribological properties of composite materials.The test piece was made with the optimal theoretical ratio of composite materials,and a tribological performance comparison test was conducted to verify the accuracy of the multiple regression equation through experiments.Observe the surface wear morphology of the spouse sub-test piece,analyze the wear mechanism and the formation of the transfer film on the upper test piece,and theoretically verify the rationality of the multiple regression equation.Finally,it is verified that the friction coefficient error of the regression equation is controlled within 5%and the wear rate error is controlled within 10%.The change trend of the regression equation is related to the wear mechanism.The optimal ratio of the composite material is 3%nano-La₂O₃and 16.77%nano-serpentine.The actual friction coefficient is 0.0391 and the actual wear rate is0.865×10^-5mm3·?N·m?-1.The composite material is made according to the optimal ratio,and the tribological test under different working conditions is performed.The statistic chart of the tribological performance changing with the working condition is analyzed,and the optimal load and the optimal moving speed of the composite material under the ratio are studied.Observe the surface wear morphology of the spouse sub-test piece,analyze the wear mechanism and the formation of the transfer film on the upper test piece,and study the influence of different working conditions on the tribological properties of the composite.The results show that the tribological properties of the composite material are optimal at a working load of 7.1 MPa;the optimal sliding speed of the composite material is 0.345 m/s under the optimal load;when the material has relatively optimal performance,the wear mechanism of the lower test piece The wear is mainly accompanied by a small amount of abrasive wear.The friction debris generated by the friction is relatively thin,the friction surface is more flat,the surface of the upper test piece has lighter scratches,and the transfer film content is relatively higher.