Research On Fabrication And Wear Resistance Of Nanoparticles/CF Reinforced PEEK Composite Materials

Polyether ether ketone （PEEK） has excellent heat resistance, flame resistance，electrical insulationand so on, which is widely used in the areas of auto parts, semiconductor, medical equipment andanalysis instruments, and etc.In order to improve the performance of PEEK and to make it to be used as fields with higherrequirements of wear resistance such as the valve block and seal parts and to replace metal materials,nano-SiO₂and nano-TiO₂were used as fillers respectively to reinforce PEEK by compression moldingin this study. The influence of the content of nano-SiO₂and nano-TiO₂on the friction and wearresistance and mechanical properties of PEEK composites were investigated. The results showed thatwhen the weight content of nano-SiO₂or nano-TiO₂was5%, the minimum specific wear rate of PEEKcomposites were1.03×10^-6mm³（/N·m）and2.84×10^-6mm³（/N·m）, compared with pure PEEK, whichwere decreased by70.23%and17.92%respectively. FESEM analysis showed that after incorporationof the nano-SiO₂or nano-TiO₂, the wear surface of PEEK composites had furrow shallow and slightplastic deformation.When adding15%CF in the above composite system, the specific wear rates of CF/SiO₂/PEEKcomposites and CF/TiO₂/PEEK composites were2.49×10^-7mm³/（N·m）and4.91×10^-7mm³/（N·m）respectively, compared with the corresponding nano-particles/PEEK composites, which were decreasedby75.83%and82.71%respectively. Compared with the pure PEEK, the specific wear rates of15wt%CF/5wt%SiO₂/PEEK composites and15wt%CF/5wt%TiO₂/PEEK composites were decreasedby92.80%and85.81%respectively.The results of mechanical properties indicated that when the weight content of CF was15%, thetensile strength and flexural strength of CF/SiO₂/PEEK composites were increased by12.90%and7.21%, the impact toughness was decreased by4.72%. Compared with the pure PEEK, there was aslight increase in the tensile strength of15wt%CF/5wt%SiO₂/PEEK composites, but the flexuralstrength and the impact toughness were only decreased by3.48%and9.22%, respectively. When theweight content of CF was15%, the tensile strength and flexural strength of CF/TiO₂/PEEK compositeswere increased by9.65%and11.96%, and there was only a slight decrease in impact toughness.Compared with the pure PEEK, the tensile strength and flexural strength were increased by3.91%and11.26%, and the impact toughness was just decreased by5.79%. In the above several compoundsystems,15wt%CF/5wt%TiO₂/PEEK composite possessed the optimum friction and wear resistance,and the influence of the mechanical properties was the minimum. FESEM analysis showed that withaddition of CF, more shallow furrow and more slight plastic deformation were existed on the wear surface, so adhesive wear and abrasive wear were still the main wear mechanism.