Development of Antifriction Materials Based on Polytetrafluoroethylene with Carbon Fibers and Tungsten Disulfide

2020 ◽  
Vol 992 ◽  
pp. 745-750
Author(s):  
A.P. Vasilev ◽  
T.S. Struchkova ◽  
A.G. Alekseev

This paper presents the results from the investigation of effect the carbon fibers with tungsten disulfide on the mechanical and tribological properties of PTFE. Is carried out a comparison of mechanical and tribological properties of polymer composites PTFE-based with carbon fibers and PTFE with complex filler (carbon fibers with tungsten disulfide). It is shown that at a content of 8 wt.% CF+1 wt.% WS2 in PTFE, wear resistance increases significantly while maintaining the tensile strength, relative elongation at break and low coefficient of friction at the level of initial PTFE. The results of X-ray analysis and investigation of SEM supramolecular structure and friction surfaces of PTFE and polymer composites are presented. It is shown that the degree of crystallinity of polymer composites increases in comparison with the initial PTFE. The images of scanning electron microscope reveal that particles of tungsten disulfide concentrating on the friction surface is likely responsible to a reduction in the coefficient of friction and increase the wear resistance of PTFE-based polymer composites with complex fillers.

2017 ◽  
Vol 30 (6) ◽  
pp. 657-666 ◽  
Author(s):  
Fangfang Li ◽  
Ying Hu ◽  
Xiaochen Hou ◽  
Xiyu Hu ◽  
Dong Jiang

In this work, the effect of thermal, mechanical, and tribological properties of the blending system of different contents of short carbon fibers (SCFs) on different-viscosity poly-ether-ether-ketone (PEEK) was reported. The composites were manufactured using injection molding technique. Mechanical and tribological properties were measured by the tensile strength, the flexural strength, the coefficient of friction, and the wear rate. The results showed that the wear resistance and mechanical properties of the PEEK with the lower viscosity appeared on a more outstanding level, and experimental results showed that PEEK composites with added 10 wt% SCFs were optimal about the tribological behaviors and mechanical properties of the composites. Furthermore, based on scanning electron microscope inspections, the situation of the friction and worn surface of the material was explained.


Tribologia ◽  
2018 ◽  
Vol 280 (4) ◽  
pp. 137-142
Author(s):  
Dagmara TRYBA ◽  
Marcin KOT ◽  
Anna ANTOSZ

Properties of high manganese austenitic cast steel are not satisfactory; therefore, this material should be hardened. Currently, the commonly used method of hardening does not allow eliminating problems related to premature wear of railway frogs. Therefore, many studies have been carried out to find an alternative method to obtain improved wear resistance of such elements. The article presents an analysis of the mechanical and tribological properties of base and hardened, by different methods, high-manganese cast steel applied for turnouts. Tests were performed for three hardening methods: explosive, pressure-rolling, and dynamic impact. The results were compared with the properties of base material after saturation treatment. The conducted tests allowed the determination of hardness profiles of hardened surfaces, as well as the wear resistance and coefficient of friction, and the obtained results are very promising. Hardening by dynamic impact provided much better results in relation to presently used explosive hardening technology.


2009 ◽  
Vol 151 ◽  
pp. 135-138
Author(s):  
Joanna Siejka-Kulczyk ◽  
Joanna Mystkowska ◽  
Małgorzata Lewandowska ◽  
Jan R. Dabrowski ◽  
Krzysztof Jan Kurzydlowski

Ceramic – polymer composites based on acrylic (bis–GMA) and urethane – methacrylate (UM) resins with a 60 % total volume fraction of filler consisting of micro particles of glass and nano-particles of silica were fabricated. The nano-silica contents were: 0, 10, 20 vol. %. The composite samples were subjected to wear tests using an occlusion simulator tester which applies reciprocating movement and cyclic loading on the test material. This method of testing provides some similarity to the masticatory pattern occurring in the mouth during eating. The enamel of a human tooth was used as a counter-sample. The coefficient of friction was determined and the wear resistance of the composite samples containing the various nano-silica contents was established. In addition, the relative influence of the composite composition on the rate of wear of the human tooth enamel was estimated. The results of the study indicate that the addition of nano-silica significantly improves the wear resistance of the ceramic – polymer composites and reduces the wear of enamel. It was found that the addition of nano-silica has no influence on the coefficient of friction. It was also established that composites based on UM resin show better wear resistance than those based on a mixture of bis-GMA and TEGDMA resin.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Kawaljit Singh Randhawa ◽  
Ashwin D. Patel

Abstract Nylon composites are of evolving interest due to their good strength, toughness, and low coefficient of friction. Various fillers like micro- and nanoparticulates of metals and metal compounds were used to enhance the mechanical and tribological properties of nylons for many years by researchers. In this paper, an overall understanding of composites, filler materials, especially particulate filler materials, application areas of polymer composites, wear of polymers, and the effect of various fillers on tribo-mechanical properties of nylons have been discussed. The detailed review is limited to micro- and nanoparticulate fillers and their influence on the mechanical and tribological properties of various nylon matrices.


Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4295
Author(s):  
Hai Wang ◽  
Annan Sun ◽  
Xiaowen Qi ◽  
Yu Dong ◽  
Bingli Fan

The tribological properties of polytetrafluoroethylene (PTFE)/AP (poly(para-phenyleneterephthalamide) (PPTA) pulp) composites under different test conditions (load: 2N, 10N; frequency: 1 Hz, 4 Hz; amplitude: 2 mm, 8 mm) were holistically evaluated. PTFE/AP composites with different AP mass ratios of 3%, 6%, and 12% as a skeleton support material were prepared. The coefficient of friction (COF) and wear rate were determined on a ball-on-disk tribometer. Furthermore, the morphology, element composition, and chemical structure of the transfer membrane were analyzed accordingly. The relationships between load, frequency, amplitude, and tribological properties were further investigated. According to the wear mechanism, AP enables effective improvement in the stiffness and wear resistance, which is also conducive to the formation of transfer films.


Tribologia ◽  
2018 ◽  
Vol 279 (3) ◽  
pp. 107-111
Author(s):  
Anita PTAK ◽  
Piotr KOWALEWSKI

For the polymeric materials, changing of the temperature causes changes in mechanical and tribological properties of sliding pairs. The goal of the present study was to determine the change in Young's modulus and kinetic friction coefficient depending of the temperature. Three thermoplastic polymers, PA6, PET and PEEK, were tested. These materials cooperated in sliding motion with a C45 construction steel disc. As part of the experiment, the Young's modulus tests (by 3-point bending method) and kinetic friction coefficient studies (using pin-on-disc stand) were carried out. The temperature range of mechanical and tribological tests was determined at T = –50°C±20°C. Comparing the results of mechanical and tribological properties, there is a tendency to decrease the coefficient of friction as the Young's modulus increases while reducing the working temperature.


2014 ◽  
Vol 591 ◽  
pp. 85-88 ◽  
Author(s):  
R. Geetha ◽  
Paulraj Jawahar

Glass filled nylon composites (GFN) and hybrid graphene oxide reinforced glass filled Nylon nanocomposites (GO-GFN) are prepared by blending the required base materials in injection molding machine at processing temperature of 275°C. The specimens prepared are subjected to various mechanical property tests to reveal their hardness, tensile strength and flexural strength. The wear discs of GFN and GO-GFN composites as per ASTM standard are injection molded to analyze the tribological properties using pin on disc tribometer. The pin used is EN 8 Tool steel. The Coefficient of friction for the GFN composites for the wear load of 10 N is 0.28. Addition of 0.003 wt% GO to the GFN system has decreased the coefficient of friction significantly to the value of 0.12. The decrease in C.O.F was correlated with the adhesion film formation in the pin surface. This work confirms the improvement in wear resistance of GO-GFN system which is attributed by the presence of graphene oxide only.


2015 ◽  
Vol 817 ◽  
pp. 143-149
Author(s):  
Shuo Wang ◽  
Kan Zhang ◽  
Xin Guo ◽  
Su Xuan Du ◽  
Mao Wen ◽  
...  

Based on previous work on lubricant hard HfCxfilm, the HfCxNyfilmswere deposited by sputtering from theHf target in a mixture of discharging N2,Ar and CH4, and the N content in films was accurately controlled by changing the N2flow rate.Theintroduction of N into the films contributed to the presence of solid solution FCC-HfC(N) and FCC-HfNphase appeared at high N content in films. In addition, the a-C content in the filmsdecreasedwith increment ofN content in the films. In comparison with HfCxfilm, hardness of HfCxNyfilms were enhanced from 21 GPa to 25 GPa with N content rising to 6.8 at.% but then surplus N in the films impaired the hardness. The coefficient of friction and surface roughness for HfCxNyfilms increasedfrom 0.10 to 0.23 and 3.13 nm to 12.4 nm, respectively, with decreasing a-C content from 52.9 at.% to 46.3 at.%. However, the introduction of N into HfCxFilm improvedthe wear resistance of filmseffectively, and the specific friction rate for this HfCxNyfilm deposited at 8 sccm N2was only 6.17×10-7mm3/Nm about half of that of HfCxfilm (1.09×10-6mm3/Nm).


2019 ◽  
Vol 799 ◽  
pp. 65-70
Author(s):  
Yuan Hao Yu ◽  
Gai Zhao ◽  
Jing Fu Song ◽  
Qing Jun Ding

The travelling waves ultrasonic motors (TWUM) with nonmagnetic, large torque, high precision and simple structure was driven by frictional force, which had been applied aerospace, intelligent and precise instruments. In order to reduce the total weight of TWUM, the phosphor bronze stator with the biggest density among the all parts of TWUM (8.89 g/cm3) were substituted with light weight polymer or polymer composites. This study designed and prepared one types of low density polyimide (PI) composite (1.41g/cm3) reinforced with carbon fibers (CF) which can reduce the weight of stator over 85%. Importantly, this PI composite can meet the main requirements of TWUM, such as high elastic modulus, wear resistance, and suitable friction coefficient. The output stalling torque of TWUM with CF/PI stator still have 0.22 N·m (18.3% compared with TWUM with phosphor bronze stator). Moreover, this study systematically investigated the mechanical and tribological properties of CF/PI composite. For comparison, the pure PI, polyetheretherketone (PEEK) and polyphenylene sulfide (PPS) were also analyzed to reveal the wear mechanisms. The experimental results indicated that CF/PI had better wear resistance and lower friction coefficient than other polymer sliding against Si3N4. This light weight polymer composites would be an ideal candidate to reduce the weight of TWUM, which can broaden the lightweight application in the field of aerospace.


2017 ◽  
Vol 898 ◽  
pp. 1424-1430
Author(s):  
Ping Ren ◽  
Mao Wen ◽  
Su Xuan Du ◽  
Q.N. Meng ◽  
Kan Zhang ◽  
...  

The NbN/Ni coatings were deposited by co-sputtering on Si (100) substrates. The structure, hardness and tribological properties were characterized by X-ray diffraction (XRD), atomic force microscope (AFM), scanning electron microscopy (SEM), nanoindentation test and ball-on-disc tribometer. XRD revealed that the NbN/Ni coatings exhibited a NaCl-type NbN structure but no sign of any nickel phase. For the coatings with various nickel powers ranged from 20 W to 40 W, the shrinkage of the lattice parameter of NbN indicated that Ni atoms might be incorporated into the NbN lattice with a substitution of Nb atoms by the smaller Ni atoms. Further increasing of Ni powers, the degree of crystallinity of the coatings became worse. The NbN coating doped with a certan power of Ni (40 W) exhibited the best degree of crystallinity among all samples. It also displayed a maximum microhardness of 25 GPa combined with a better resistance to plastic deformation, which could attribute to the grain refinement and the solid solution strengthening. Tribilogical properties of NbN/Ni coatings were also found to be depentent on nickel powers significantly. For the pure NbN coating, the coefficient of friction (CoF) was 0.7 approximately, while it decreased to 0.54 when the power of Ni increased to 40 W. Simultaneously, the wear resistance of the NbN/Ni coatings was improved due to the spontaneous oxidation of the wear track surfaces caused by the addition of a certain amount of nickel to the niobium nitride coatings.


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