Study Of The Performance Of Polyether Ether Ketone (PEEK) Composite Using On Non-lubricated CNG Compressor

Since it is impossible to achieve lubrication without oil in Compressed Natural Gas(CNG) compressor which is used on the field of natural gas generally, some requirements should be satisfied, such as the mechanical properties, the friction and wear properties, the high temperature resistance and the oil resistance of the piston rings and the sealing fillers assembled in the important parts by using PEEK composite. The aim of the paper is to achieve non-lubrication in CNG compressor by studying the formula of the PEEK composite and its performance, and finally provide basic data and the theoretical basis to upgrade the level of the manufacture and the design of compressor in our country.In this paper, sixteen kinds of PEEK composite formula is designed according to the actual working conditions of non-lubricated CNG compressor, especially in the collaborative modification research of the material properties of PEEK. This paper studied the changes of the properties for injection molding PEEK composite based on the different PEEK filler, such as the short carbon fiber(SCF), short glass fiber(SGF), polytetrafluoroethylene(PTFE), expanded graphite(EG) and nanometer materials(TiO2) etc. Five kinds of filler in PEEK composite material with different content as well as the influence to properties were also analyzed. At the same time scanning electron microscopy (SEM) was used to observe PEEK tensile specimen’s fracture surface and the friction-and-wear of the worn surface.The changes to the mechanism of its performance were explored from the microstructure point of view. Besides, this paper also studies the thermal properties of the PEEK composites and the effect trend that high temperature treatment on PEEK composite material mechanics properties.Results show that, because interface of SCF and SGF with PEEK matrix had good bonding ability, Suitable SCF and SGF can prove both mechanical properties and thermal expansion performance of composite PEEK, while the SCF has a more significant result.For the poor stickiness of both PTFE and EG to PEEK, the mechanical property of the composite declined while friction and wear performance improved. Addition of suitable amount of TiO2can improve the mechanical and friction and wear performance of the composite remarkably, with a content of5%, PEEK has a best combination property. Besides combination property can be much better by proper high-temperature treatment. Meanwhile, PEEK composite has the good performance on oil resistance. The result shows that one that obtained by sample15 has the best comprehensive properties, which means it has the great friction and wear properties while the high temperature resistance and the oil resistance of it are good enough to meet the demands of the piston rings and the sealing fillers.