Research On Bio-Tribological Properties And Surface Textures Modification Of PEEK/Ceramics

With the aging population expanding,there is an urgent need for orthopaedic implants materials with better biological friction properties.After half a century of development,polymer/ceramic friction pairs have been favored by joint replacement.Polymer/ceramic friction pair belongs to soft-on-hard combination,which overcomes the disadvantages of poor impact resistance of hard-on-hard and effectively avoids the problems of poor strength of soft-on-soft combination.And ceramic materials have good tribological properties.Therefore,it is a new challenge to find polymer/ceramic joint pairs with excellent tribological properties.Firstly,the friction and wear properties of polymers（PEEK,PE）articulating against ceramics（Si₃N₄ and Al₂O₃）were systematically compared through experiments.The results show that PEEK material has lower wear rate than PE material.However,because the hardness of PE is lower than that of PEEK,the degree of fatigue and abrasive wear is higher than that of PEEK.Si₃N₄ is prone to tribo-chemical reaction,forming Si O₂ protective layer on its surface to improve its friction and wear properties.Then,the friction and wear properties of PEEK materials（PEEK,CF-PEEK）articulating against Si₃N₄ under various tribological conditions were investigated,and the friction and wear mechanism of PEEK and Si₃N₄ was studied by molecular dynamics（MD）simulation.The experimental and simulation results show that in DPPC lubricating medium,DPPC will self-assemble and self-adsorb on the surface of PEEK to form lubricating film and improve the friction and wear performance.However,the carbon fiber in CF-PEEK will affect the integrity of DPPC lubricating film on its surface,resulting in the wear rate of CF-PEEK being greater than that of PEEK.At last,the effect of surface texture on the biological tribological behavior of PEEK materials（PEEK,CF-PEEK）articulating against Si₃N₄ was investigated.The results show that there is a synergistic effect between surface texture and DPPC lubricating medium,which can improve the friction and wear properties of PEEK materials.In DPPC,the texture of most PEEK can reduce the wear rate through synergistic effect.