| Polyether ether ketone(PEEK)has excellent mechanical properties,outstanding resistance to media,and heat resistance.Based on its excellent self-lubricating properties,it can be widely used in aerospace,automotive manufacturing,biomedical and other fields.Fused deposition modeling(FDM)technology is simple in process and can mold devices with complex structures.Combining this advantage to achieve differentiated customization of tribological components will provide a new idea for the application of PEEK materials in the field of tribology.In this paper,the effects of FDM molding process,annealing treatment,and rubber plastic blending on the mechanical properties and friction and wear properties of PEEK materials were investigated,and their wear mechanisms were studied.The specific research contents and results are as follows:(1)The effects of FDM molding parameters(nozzle temperature,platform temperature,layer thickness and printing speed)on the mechanical and tribological properties of PEEK materials were investigated through orthogonal experimental design.The research results show that: Nozzle temperature and printing speed are the main factors that affect the mechanical properties of PEEK materials formed by FDM.Higher nozzle temperature and lower printing speed contribute to improving the mechanical properties of materials.Combining the range analysis of mechanical properties and the characterization of interfacial bonding properties by micro convex scratches,the optimal molding process for PEEK was optimized: nozzle temperature 440 ℃,platform temperature 110 ℃,printing speed 40 mm/s,and layer thickness 0.2 mm.The friction coefficient and wear rate of PEEK significantly decrease with the increase in nozzle temperature,while the wear resistance increases with the increase in material ductility.(2)The PEEK material formed under the optimal FDM process conditions was annealed,and the effect of annealing temperature on its mechanical properties and friction and wear properties was investigated.The mechanical strength increases with the increase in annealing temperature,as the increase in annealing temperature helps to improve the defects and pores between printed wires,improve interfacial bonding,and thereby improve the mechanical properties of PEEK.The wear rate of PEEK exhibits a minimum at an annealing temperature of 200 ℃ and a parallel contact mode.The wear surface mainly exhibits slight scratches,and abrasive wear is the main wear mechanism.(3)The in situ compatibilization of PEEK/IR composites was achieved by using isoprene rubber(IR)and FDM molded PEEK skeleton materials and grafting modification of the PEEK skeleton.Under the same friction condition,composite materials have lower friction coefficient and wear rate than pure PEEK,and the friction coefficient of composite materials significantly decreases with the increase of sliding speed.When the sliding speed is 2.5 m/s,the wear rate of composite materials is 65%lower than pure PEEK.As the normal load increases,the friction coefficient and wear rate of the composite exhibit an approximately linear downward trend,which is attributed to the formation of an oil film on the surface of the steel ring by isoprene rubber,which reduces the friction resistance of the composite during the friction process.At the same time,a high mass transfer film is formed on the surface of the steel ring of the composite,and the decrease in material loss leads to a decrease in the wear rate.When the load is 125 N,the wear rate of the composite decreases by 76% compared to pure PEEK.The wear resistance of pure PEEK under high load is poor,and the main wear mechanism is adhesive wear. |
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