Study On The Friction And Wear Properties Of Porous PEEK Composites And Numerical Simulation Of The Properties

There are abundant pores in the internal of porous lubricating polymer materials.The pores can inhale and storage oil so that the pores can continuously provide lubricating oil at the coupling of temperature and stress conditions.The lubricating oil can play a role of self-lubricating,which makes the porous lubricating polymer materials have broad application prospects.An attempt had been made to prepare porous MWCNTs/PEEK self-lubricating composites by molding-leaching and vacuum melting process under high temperature condition.NaCl was used as pore-forming agent and PEEK as matrix.The effects of MWCNTs content and load on the tribological properties of the new porous PEEK self-lubricating composites were investigated.The wear mechanisms were discussed by the SEM of worn surfaces,counterpart surfaces and cross-section.Then the relationship between the frictional heat,friction coefficient,contact pressure and the temperature was studied by using the finite element simulation method.To further reveal the inherent mechanism of the pore structure-performance and the mechanism of formation film on the friction surface,the ANSYS software was used.ANSYS software analyzed the pore size and porosity effecting on the material mechanical properties and tribological properties under the coupling of frictional heat-stress field.The main contents of this work are summarized as follows.1.Compared with pure PEEK under dry sliding condition,the friction coefficient of porous PEEK composites reduced 86%and wear resistance increased 303 times.So the porous PEEK composites showed synergistic effect on improving the wear resistance of PEEK.When the content of micron pore-forming agent and MWCNTs was 30 wt%,5 wt%and the pores was impregnated with lithium-base grease,the friction coefficient and wear rate of nano-micro pores self-lubricating PEEK reached the lowest level,which were recorded as 0.0213 and 1.12×10-15m3/(Nm),respectively.2.Based on the friction heat characteristics of polyetheretherketone(PEEK)under the continuous ring rotating friction movement,a two-dimensional axisymmetric model established by using the finite element method.The friction coefficient,filler types and load effect on the temperature field of PEEK composites were investigated.The effect of surface friction heat on the tribological properties of the composite materials was analyzed.The real-time temperature distribution was studied.Finally,pure PEEK was selected to verify the feasibility of the simulation method.The friction coefficient,wear rate,maximum friction temperature of PEEK matrix composites can be obtained through the experiment.The results show that the maximum simulated temperature compared to the measured is less than 2%and the most important is the finite element method can predict accurately the temperature values at anytime and anywhere in the friction process.So the results provide references for the tribological application and designing of resin matrix composite.3.According to the characteristics structural of self-lubricating sintered materials,a finite element analysis model was established to analyze the lubricating grease overflowed from pores at high-temperature.The self-lubricating mechanisms under the coupling of frictional heat and stress were studied.The results will be contributed to indicate the lubricant depth of the self-lubricating materials and the life of the self-lubricating material.So the simulation results provide the basis for the designing and controlling of high temperature sweating lubrication materials.