Study On Design,preparation And Tribological Properties Of PEEK Based High Temperature Self-lubrication Composites

With the rapid development of automobile,aerospace and other industries,the demand for the working condition of engineering plastic gear in this field is becoming increasingly harsh.Engineering plastic gear often easily has some failure forms,such as the break of its teeth,the wear of its surface.Therefore,the preparation of high strength self-lubrication composites with strong toughness and high temperature self-lubrication properties is of great significance to improve the application of engineering plastic gear and prolong the service life.In this article that is based on polymer faculties and alloying technology and combined with the synergy of multivariate composite filler modification mechanism,PEEK based high temperature self-lubrication composites was designed and prepared,and its physical,mechanical,thermal properties and tribological performance were analyzed systemtically.The matrix of composites was studied by using solubility parameter combined with glass transition temperature.Results showed that the compatibility of PEEK/PEI/PES ternary matrix was better,and the mass ratio of matrix was determined to 85/10/5.Based on the wear resistance and reinforcement principle of composites,different contents of short carbon fiber?SCF?,molybdenum disulfide?MoS₂?,potassium titanate whisker?PTW?and titanium dioxide?TiO₂?were added as reinforced phase of composites.The relationship between the composition and composition ratio of additive and the friction coefficient,bending strength and temperature rise due to friction heat production of the composites was studied by combining traditional mathematical model with finite element analysis.The composites were prepared by vacuum hot pressing sintering method and the mechanical properties and thermal properties were tested.Results showed that the bending strength hardness and thermal performance of the composites were obviously enhanced.With the increase of MoS₂,PTW and TiO₂ content,the bending strength of the composites increased firstly and then decreased,while increased with the increase of SCF content.Under the condition of dry fiction,the fiction and wear experiment of composites were tested by high temperature friction and wear test machine.Results showed that due to the synergistic effect of additive,the tribological properties of PEEK based high temperature self-lubrication composites were improved.With the increase of SCF and MoS₂ content,thefrictioncoefficient and wear rate of composites decreased firstly and then increased;with the increase of PTW content,the friction coefficient and wear rate of composites decreased gradually;with the increase of TiO₂ content,the friction coefficient of composites decreased firstly and then increased,while the wear rate of composites increased gradually.When the mass fraction of SCF,MoS₂ and PTW is 10%,10% and 15% respectively,the tribological properties of PEEK based high temperature self-lubrceation composites were the best,and the friction coefficient and wear rate of composites was 0.25 and 1.65 ? 10-8cm3·N-1·m-1respectively.Compared with the test speed and load,the change of temperature had a great influence on the tribological properties of composites.With the increase of temperature,the friction coefficient of composites decreased firstly and then increased,while the wear rate increased gradually.When the test temperature was 100?,the friction coefficient of the composites reaches the minimum value,and the suitable temperature condition of the composites is 0 ¹50?.The friction and wear surfaces of the composites were analyzed by SEM and XRD in order to research its self-lubrication mechanism.