Effects of Lubricants on the Friction and Wear Properties of PTFE and POM

2005 ◽  
Vol 127 (4) ◽  
pp. 766-775 ◽  
Author(s):  
H. S. Benabdallah ◽  
J. J. Wei

The friction and wear properties of PTFE and POM were investigated using a ball-on-steel ring tester under dry and lubricated conditions by paraffin and 10W–30 oils. SEM, EDAX, FTIR, and surface wettability techniques were used to characterize and assess the morphology and chemical composition of the original surfaces, as well as the wear track, transfer film, and wear debris at different loads and speeds. Although the friction was high, similar behavior to that reported in the literature was observed. The experimentally determined surface temperature of the plastic revealed optimum loading levels, for each sliding speed, at which the friction and wear rate become a minimum and the thermal effect stabilizes. In boundary-like lubrication using both oils, friction and wear were significantly reduced with the exception of an increase in wear rate with load when POM was lubricated by 10W–30 oil. Surface analysis revealed that the formation of lubricative protective layers on the surfaces in contact is crucial to reducing friction, and more importantly, wear. FTIR results confirmed that film transfer occurs in the case of POM.

Author(s):  
Habib S. Benabdallah ◽  
Jianjun J. Wei

The friction and wear properties of PTFE and POM were investigated using a ball-on-steel ring tester under dry conditions and conditions lubricated by paraffin and 10W-30 oils. SEM, EDAX, FT-IR and surface wettability techniques were used to characterize and assess the morphology and chemical composition of the original surfaces as well as wear track, transfer film and wear debris for different loads and speeds. Although the friction was high, similar behaviours to those reported were observed. The experimentally determined surface temperature of the plastic revealed optimum loading levels for each sliding speed at which the friction and wear rates become minimal and the thermal effect stabilizes. In boundary-like lubrication using both oils, friction and wear were significantly reduced with the exception of an increase in wear rate with load when POM was lubricated with 10W-30 oil. Surface analysis revealed that the formation of lubricious protective layers on the surfaces in contact is crucial to reducing friction and more importantly wear. FT-IR results confirmed that film transfer occurs in the case of POM.


Author(s):  
Y. Sakano ◽  
T. Iwai ◽  
Y. Shoukaku

The friction and wear properties of polymer were investigated under a hydrogen atmosphere, by using PTFE (polytetrafluoroethylene) and two kinds of PTFE composites. Experiments were also conducted in air, nitrogen, and vacuum environment. The experiment carried out by pin-on-disk friction and wears apparatus in the vacuum chamber. Pin specimens are no filling PTFE, Gr-filled PTFE (Gr filled with 25 wt%) and MoS2–filled PTFE (MoS2 filled with 25 wt%). Friction disk is aluminum alloy 6061-T6 with 0.02μm surface roughness. Aluminum alloy 6061-T6 is able to use for apparatus for hydrogen. After experiments, specific wear rate was calculated, specimen surface, wear track and wear debris were observed, surface profile of the wear track were measured. The specific wear rate of unfilled PTFE and PTFE/MoS2 of in air was lower than the other atmospheres. The A6061-T6 disk was worn by PTFE pin specimens and in the case of wear track was much rougher, the specific wear rate of pin specimens tended to increase without unfilled PTFE in air and PTFE/Gr.


2018 ◽  
Vol 70 (9) ◽  
pp. 1706-1713 ◽  
Author(s):  
Guotao Zhang ◽  
Yanguo Yin ◽  
Ting Xie ◽  
Dan Li ◽  
Ming Xu ◽  
...  

Purpose This paper aims to obtain high mechanical and good tribological properties of epoxy resin-based coatings under dry friction conditions. Design/methodology/approach Bonded solid lubricant coatings containing Kevlar fibres were prepared by a spraying method. The friction and wear properties of the coatings were experimentally investigated with a face-to-face tribometre under dry friction conditions. Scanning electron microscopy, energy dispersive X-ray spectroscopy and 3D laser scanning technologies were used to characterise the tribological properties. The action mechanism of the Kevlar fibres on a solid lubricant transfer film was also analysed. Findings Adding Kevlar fibres can significantly improve the wear resistance of the coatings. When the Kevlar fibre content increases, the tribological properties of the coatings improve and then worsen. Superior properties are obtained with 0.03 g of Kevlar fibres. Appropriately increasing the load or speed is beneficial to the removal of the outer epoxy resin and the formation of a lubricant film. During friction, the solid lubricants wrapped in the epoxy resin accumulate on the surface to form a transfer film that shows a good self-lubricating performance. In the later friction stage, fatigue cracks occur on the solid lubricant film but cannot connect to one another because of the high wear resistance and the entanglement of the rod-like Kevlar fibres. Thus, no large-area film falls from the matrix, thereby ensuring the long-term functioning of solid lubricant coatings. Originality/value Epoxy resin-based solid lubricant coatings modified by Kevlar fibres were prepared, and their friction and wear properties were investigated. Their tribological mechanisms were also proposed. This work provided a basis for the analysis of the tribological properties and design of bonded solid lubricant coatings containing Kevlar fibres.


2017 ◽  
Vol 733 ◽  
pp. 60-64
Author(s):  
Munir Tasdemir ◽  
Ozkan Gulsoy

In the present work, the friction and wear properties of Polypropylene (PP) based composites filled with Hydroxyapatite (HA) particles were studied. Fillers contents in the PP were 10, 20, and 30 wt%. The effects of hydroxyapatite ratio on the water absorption, friction and wear properties of the polymer composites is presented. The result showed that the addition of HA to the composite changed the water absorption, friction coefficient and wear rate.


1992 ◽  
Vol 114 (1) ◽  
pp. 131-140 ◽  
Author(s):  
K. Komvopoulos ◽  
H. Li

The processes of tribofilm formation and disruption and the predominant tribo-mechanisms of unlubricated ceramic materials were investigated experimentally. Sliding experiments in humidity controlled atmospheres revealed that the formation of interfacial tribofilms significantly affects the steady-state friction and wear properties of ceramics. Scanning electron microscopy and various composition analysis techniques demonstrated that although tribochemical reactions might occur, the principal mechanisms of tribofilm formation were the generation, agglomeration, and compaction of fine wear debris produced from both sliding surfaces. The tribofilms exhibited different tribological characteristics, depending on their elemental compositions and the humidity. For all the ceramic pairs tested, the steady-state coefficients of friction decreased with relative humidity. In contrast to the conventional fracture toughness approach, surface profilometry and microscopy studies showed that the highest wear rates were encountered with the toughest ceramic. Plowing grooves parallel to the direction of sliding, fine wear debris of round and cylindrical shapes, microcracking, and localized delamination of the tribofilms were identified. Microscopic observations suggested that damage of the subsurface material adjacent to the interface of the tribofilms was immeasurable. Qualitative comparison of the topographical features of worn surfaces indicated that, depending on the humidity and the type of ceramic, microplasticity, microfracture, and delamination of the tribofilms were the prevailing steady-state tribomechanisms.


2014 ◽  
Vol 8 (1) ◽  
pp. 125-128 ◽  
Author(s):  
Tao Ding ◽  
Wenjing Xuan ◽  
Qiudong He ◽  
Hao Wu ◽  
Wei Xiong

A series of experiments on friction and wear properties of carbon strip rubbing against copper contact wire is performed on high-speed friction and wear tester with electric current. The results show that the friction coefficient is generally maintained between 0.24 and 0.37. In the absence of electric current, the coefficient of friction is higher than that in the presence of electric current. The wear rate of carbon strip materials is generally not more than 0.014g/km. In particular, the wear rate under the electric current of 240 A is 14 times more than that in the absence of electric current. By observing the scar of worn surface with optical microscope, it can be found that there are obvious slip scars and arc erosive pits. The dominated wear mechanisms are abrasive wear and arc erosion in electrical sliding frictional process.


2008 ◽  
Vol 368-372 ◽  
pp. 961-963
Author(s):  
Hou An Zhang ◽  
Xiao Pin Hu ◽  
Wei Cheng Tan ◽  
Cun Shi

MoSi2 was prepared by SHS, and then pressed under 300 MPa at room temperature and sintered at 1600 °C for 1 h in a vacuum furnace. The tribological properties of MoSi2 against Al2O3 in the temperature range from 700°C to 1100 °C were investigated. Microphotographs and phases of the worn surface of MoSi2 were observed by SEM and XRD. Results showed that MoSi2 has well friction and wear properties below 900 °C. When temperature rises from 900 °C to 1000 °C, wear rate of MoSi2 is raised by 20.8% which is attribute to the change of wear mechanism. The main wear mechanisms of MoSi2 are adhesion and oxidation at high temperatures. When over 900 °C, because of ductile - brittle transition characteristic of this material, plastic deformation and fracture are also found on the worn surface of MoSi2. This leads to the high wear rate of MoSi2.


Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4547
Author(s):  
Bin Yang ◽  
Aiqin Wang ◽  
Kunding Liu ◽  
Chenlu Liu ◽  
Jingpei Xie ◽  
...  

SiCp/Al-Si composites with different CeO2 contents were prepared by a powder metallurgy method. The effect of CeO2 content on mechanical properties, friction and wear properties of the composites was studied. The results show that with the increase in CeO2 content from 0 to 1.8 wt%, the density, hardness, friction coefficient of the composites first increases and then decreases, the coefficient of thermal expansion (CTE) and wear rate of the composites first decreases and then increases. When the content of CeO2 was 0.6 wt%, the density and hardness of the composite reached the maximum value of 98.54% and 113.7 HBW, respectively, the CTE of the composite reached the minimum value of 11.1 × 10−6 K−1, the friction coefficient and wear rate of the composite reached the maximum value of 0.32 and the minimum value of 1.02 mg/m, respectively. CeO2 has little effect on the wear mechanism of composites, and the wear mechanism of composites with different CeO2 content is mainly abrasive wear under the load of 550 N. Compared with the content of CeO2, load has a great influence on the wear properties of the composites. The wear mechanism of the composites is mainly oxidation wear and abrasive wear under low load. With the increase in load, the wear degree of abrasive particles is aggravated, and adhesive wear occurs under higher load.


2014 ◽  
Vol 788 ◽  
pp. 621-626 ◽  
Author(s):  
Jing Dan Wei ◽  
Hua Chen

Cu-based friction materials were prepared by powder metallurgy technology. The effect of the graphite on friction and wear properties of materials was investigated. The experimental results indicate that the wear rate of the materials increased with increasing speed. The wear rate of the materials with the graphite with the size of 300~600μm decreased with increasing graphite content, indicating that the graphite size of 300~600μm showed the good lubricating effect. The lubricating film made the friction coefficient decrease. The wear resistance of materials with 100~300μm graphite was degraded at high graphite content, and the graphite size of 100~300μm has bad effect on the strength of materials. The wear debris made the friction coefficient slightly increase with the increase of graphite content. The material with the graphite content of 10% and the graphite size of 300~600μm has the best friction and wear properties.


2020 ◽  
Vol 984 ◽  
pp. 125-130 ◽  
Author(s):  
Tian Guo Wang ◽  
X.Y. Liu ◽  
J.J. Hua

Cu-based friction materials were prepared by powder metallurgy technology. The effect of Fe content on friction and wear properties of Cu-based friction materials has been investigated. The results indicate that Fe content has great effects on the wear ability of Cu-based friction materials. Fe works as frictional component in copper-based friction materials, influening the mechanical and frictional property of materials. With increasing Fe content, the hardness and friction coefficient of Cu-based friction materials stability increase, the wear rate of the friction materials decreases. When Fe content is 6%, the materials posses stably high friction factors, as well as good wear ability.


Sign in / Sign up

Export Citation Format

Share Document