Research On Preparation And Tribological Properties Of PEEK-Based Lubrication Reinforced Composites

Polymer tribological materials have the advantages of low density,corrosion resistance,good self-lubrication and good compliance with metal friction parts.However,this kind of tribological material often has low hardness,poor creep resistance and easy to wear in the use process,so it needs to be reinforced by composite modification.In this paper,PEEK-based lubrication reinforced composites were prepared by adding lubrication reinforcing phases.The tribological properties of lubrication reinforcing phases and their additions under different friction conditions were studied,and the optimum addition formula and friction conditions were obtained.The main contents include:(1)According to the forming process of PEEK composites,a moulding device was developed to meet the requirements of the moulding process.PEEK-based lubrication reinforced composites were prepared by moulding at 390?,3MPa and 55min.The mechanical and thermal properties of the composites were characterized.The results showed that the degradation temperature and tensile strength of graphene/PEEK composites were increased.The degradation temperature of graphite fluoride/PEEK composites increases but the tensile strength decreases,while the hardness and thermal stability of molybdenum disulfide/PEEK composites increase.(2)The friction coefficient,wear volume and wear mechanism of PEEK and its composites were studied experimentally.The results show that the friction coefficient and wear volume of graphene/PEEK composites are smaller than those of pure PEEK composites under dry friction conditions(p=50N,n=500r/min).And with the increase of the content,they shows that they decreases first and then increases.When graphene content was 0.5wt%,the friction coefficient and wear volume reached the lowest values,respectively,which were 8.50%and 33.33%lower than those of pure PEEK materials.The friction coefficient and wear volume of graphite fluoride/PEEK decrease first and then increase with the increase of content.The lowest value of friction coefficient is at 0.3wt%,which is 5.33%lower than that of pure PEEK.The lowest value of wear volume is at 0.5wt%,which is 32.2%lower than that of pure PEEK.The friction coefficient of molybdenum disulfide/PEEK decreases with the increase of molybdenum disulfide content.The wear volume increases first and then decreases with the increase of molybdenum disulfide content.The maximum wear volume at 15wt%is 2.86%lower than that of pure PEEK,and the minimum wear volume at 5wt%is 37.53%lower than that of pure PEEK.The friction coefficient and wear volume of graphene/PEEK composites are smaller than those of pure PEEK composites under dry friction conditions(p=150N,n=1200r/min).The friction coefficient and wear volume of graphene/PEEK composites decrease first and then increase with the increase of graphene content.When graphene content is 0.5wt%,the minimum values of friction coefficient and wear volume are decreased by 11.54%and 38.35%respectively.Friction coefficient and wear volume of graphite fluoride/PEEK decrease first and then increase with the increase of content.Friction coefficient and wear volume reach the lowest value at 0.3wt%,which are 7.9%and 26.8%lower than that of pure PEEK.The friction coefficient and wear volume of molybdenum disulfide/PEEK decrease with the increase of molybdenum disulfide content.The wear mechanism of composites is generally abrasive wear under(p=50N,n=500r/min)conditions and adhesive wear under(p=150N,n=1200r/min)conditions,and will change with the content of additives and additives.(3)Using orthogonal test,it is concluded that the optimum ratio of graphene/graphite fluoride/molybdenum disulfide/PEEK composites is 0.7wt%graphene,0.3wt%graphite fluoride and 20wt%molybdenum disulfide under the friction conditions of(p=5ON,n=500r/min)and(p=150N,n=1200r/min).The regression model of friction coefficient and wear volume of composite material and pure PEEK material under the friction condition range(p=40-180N,n=400?1800r/min)was obtained by uniform test.The regression model showed that the wear reduction and wear resistance of the optimal scheme were significantly improved in the friction condition range(p=40-180N,n=400-1800r/min).