Preparation And Performance Study Of PEEK-Based Composite Material For Marine Sliding Bearing Bushes

China is the world’s largest civil shipbuilding power,but also a major manufacturer of naval ships.The world situation is changing rapidly,western countries are under heavy pressure on China’s economy and military,and China urgently needs to develop its own high-end marine engineering equipment.Compared with other construction machinery and equipment,sliding bearings used for high-end marine engineering equipment have the characteristics of large shaft diameter,large load bearing and high working life requirements,especially the sliding bearings for warships,in marine lubrication system damage and other abnormal circumstances,the requirements are suitable for dry friction,dilute oil lubrication and oil-water mixed lubrication,the requirements of the plain bearing can cut off the oil for more than 10 minutes,in the seawater lubrication condition,can run continuously for at least 96 hours,this poses great challenges in terms of the performance of its plain bearings and the performance of the bearing material.Taking marine plain bearings as the research object,the problem of bearings that are easy to burn out and fail under damage to marine lubrication systems and other extreme working conditions is studied in depth.For the preparation of polyetheretherketone（PEEK）composite bearings,the blend modification method will be mainly adopted,focusing on the improvement of friction and wear properties and mechanical properties of composite materials to meet the needs of ships in extreme working conditions.Specific work content includes:（1）Screening of bearing surface substrates that are currently suitable for water/oil lubrication and other working conditions.Through the comprehensive evaluation of the properties of various materials and the consideration of the compatibility between the materials,the best properties of a certain aspect of the material are fully reflected in the prepared composite materials,and the matrix of the prepared composite materials is determined to be PEEK.PTFE,the additives are PTFE,CF and MoS₂.（2）Due to the large number of additive types,in order to reduce the time of testing:on the one hand,the formula is designed by orthogonal test method,and 9 kinds of PEEK matrix composites with different proportions are prepared by hot compression molding process,and the best ratio scheme is explored more quickly;On the other hand,a special sintering mold is designed for the preparation of composite materials,which greatly improves the test efficiency.（3）To study the effect of different contents of additives on the friction and wear properties of PEEK composites:the friction coefficient and wear amount of 9 samples with different ratios are measured under dry friction,seawater lubrication and oil lubrication conditions by orthogonal experimental design.The range analysis method is used to determine the ratios of the composite materials with the smallest friction coefficient under different lubrication conditions.（4）To study the effect of different contents of additives on the physical and mechanical properties of PEEK composites:the relative density,Shore hardness,tensile strength and compressive strength of 9 kinds of samples are tested respectively.The range analysis method is used to process the test results to determine the optimal proportioning scheme of mechanical properties.（5）To study the effect of different working conditions on the friction and wear properties of PEEK composites:the friction and wear tests of sliding bearings under different loads,rotational speeds and lubrication conditions are carried out simulating the actual working conditions of ships,and the micro-morphology of the worn surface is analyzed by scanning electron microscopy and ultra-depth-of-field microscopy to explore the wear mechanism of composite materials under different working conditions.Overcoming the key technologies of marine sliding bearing materials and realizing industrialization,shortening the gap with foreign products,is of great guiding significance for the development of high reliability and high stability marine bearing products at the international advanced level and for improving the technical level of China’s bearing industry.