scholarly journals Wear Life of Bonded MoS2 Film Lubricant

2021 ◽  
Author(s):  
Naofumi Hiraoka
Keyword(s):  
Fatigue Life ◽  
Wear Rate ◽  
Friction And Wear ◽  
Solid Lubricants ◽  
Careful Consideration ◽  
Specific Wear Rate ◽  
Wear Life ◽  
Mos2 Film ◽  
Pre Treatment ◽  
Lubrication Properties

Bonded MoS2 film lubricants are widely used in industry as solid lubricants. It has excellent lubrication properties, but it also has characteristics that require careful consideration. As is well known, its friction and wear are greatly affected by the environmental atmosphere and its wear life depends on the pre-treatment of the substrate. It was found that in many cases the wear life could not be correctly estimated by a specific wear rate and could be explained by the fatigue life, especially under high loading conditions. The atmosphere dependent wear life can also be explained by the fatigue life.

Friction and Wear Behaviors of Solid Lubricants/Polyimide Composites in Liquid Mediums

2010 ◽  
Vol 654-656 ◽  
pp. 2763-2766 ◽  
Author(s):  
Li Wen Mu ◽  
Xin Feng ◽  
Yi Jun Shi ◽  
Huai Yuan Wang ◽  
Xiao Hua Lu
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Alkaline Solution ◽  
Dry Friction ◽  
Friction And Wear ◽  
Solid Lubricants ◽  
Polyimide Composites ◽  
Inorganic Fillers ◽  
Ptfe Composites

The tribological properties of polyimide (PI) composites reinforced with graphite or MoS2 sliding in liquid alkali and water as well as dry friction were investigated using a ring-on-ring tester. The results show that the friction coefficient (μ) and wear rate (W) for both graphite/PI and MoS2/PI composites in different liquid mediums are μdry>μwater >μalkali and Wwater>Wdry >Walkali. Results also indicate that the friction coefficient and wear rate of the PI composites filled with different solid lubricants are μMoS2 >μgraphite and W MoS2 >Wgraphite in different liquid mediums. In addition, the hydrophobic inorganic fillers are fit for the reinforcement of polymer-based composites sliding in liquid mediums. It is also concluded from the authors’ work that the wear rate and friction coefficient of polymer-based (such as PI, PTFE) composites in the alkali lubricated conditions is lowest among all the friction conditions. This may be attributed to the ionic hydration in the alkaline solution.

scholarly journals Development of Highly Hydrogenated DLC Coatings for Solid Lubricant Applications in Space

2005 ◽  
Author(s):  
A. Vanhulsel ◽  
R. Jacobs ◽  
K. Van Acker ◽  
E. Roberts ◽  
F. Velasco ◽  
...  
Keyword(s):  
Wear Rate ◽  
Friction And Wear ◽  
Applied Load ◽  
Solid Lubricant ◽  
Solid Lubricants ◽  
Ambient Atmosphere ◽  
Test Environment ◽  
Load Range ◽  
Dlc Coatings ◽  
Aisi 52100 Steel

The development of advanced solid lubricants is of considerable importance to space tribology. The most common solid lubricant coatings today are based on MoS2, lead or PTFE. However, none of these coatings can simultaneously fulfill all specifications, with regard to friction and wear, under ambient atmosphere and in vacuum. Consequently research is currently being aimed at further improvements in advanced solid lubricant coatings. One approach is to optimize Diamond Like Carbon (DLC) coatings to meet the specifications. In this study, the feasibility of highly hydrogenated DLC coatings (∼ 50 at% hydrogen) for solid lubricant applications is assessed. The coatings were deposited on AISI 52100 steel substrates and tested in ball-on-disc tribometers in air, vacuum and dry nitrogen environments. It was found that the test environment has the most decisive effect on both friction and wear rate, while these parameters are only slightly affected by varying the applied load under a given atmosphere. It was concluded that highly hydrogenated DLC coatings are capable of yielding ultra-low friction values in vacuum (μ = 0.008). The average friction coefficient range obtained in humid air, dry nitrogen and vacuum for the range of applied loads were respectively 0.22 to 0.27, 0.02 to 0.03, and 0.007 to 0.013. Coating lifetime was over 100 000 cycles for the entire load range tested in air and nitrogen, but was affected by the applied load as far as tests in vacuum are considered. The specific wear rate was lower than 1×10–5 mm3 N-1 m-1 under all test conditions, which was considered favourable.

Effect of Various Nanoparticles on Friction and Wear Properties of Glass Fiber Reinforced Epoxy Composites

2010 ◽  
Vol 150-151 ◽  
pp. 1106-1109 ◽  
Author(s):  
Yong Kun Wang ◽  
Li Chen ◽  
Zhi Wei Xu
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Glass Fiber ◽  
Friction And Wear ◽  
Wear Behavior ◽  
Specific Wear Rate ◽  
Wear Properties ◽  
Nano Tio2 ◽  
Nano Sio2 ◽  
Multi Walled Carbon Nanotubes

The glass fiber (GF) reinforced epoxy (EP) composites filled by nano-Al2O3, nano-TiO2, nano-SiO2 and multi-walled carbon nanotubes (MWCNTs) were prepared. The friction and wear behavior of composites under dry condition were evaluated with block-on-ring friction and wear tester. The morphologies of the worn surfaces of the composites were analyzed by scanning electric microscopy (SEM). The results show that 0.5 wt% MWCNTs and nano-TiO2 can significantly lower the friction coefficient and specific wear rate of composites, respectively, while 0.5 wt% nano-SiO2 and nano-Al2O3 can slightly lower the friction coefficient and specific wear rate of the composites.

scholarly journals Friction and Wear Behavior of Polyimide Composites Reinforced by Surface-Modified Poly-p-Phenylenebenzobisoxazole (PBO) Fibers in High Ambient Temperatures

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1805
Author(s):  
Yu ◽  
Zhang ◽  
Tang ◽  
Gao
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Friction And Wear ◽  
Wear Behavior ◽  
Specific Wear Rate ◽  
Interface Properties ◽  
Sliding Velocity ◽  
Friction And Wear Behavior ◽  
Ambient Temperatures

(1) In order to improve the properties of antifriction and wear resistance of polyimide (PI) composite under high temperature conditions, (2) 3-Aminopropyltriethoxysilane (APTES) and Lanthanum (La) salt modifications were employed to manufacture poly-p-phenylenebenzobisoxazole (PBO)/PI composites with different interface properties. The representative ambient temperatures of 130 and 260 °C were chosen to study the friction and wear behavior of composites with different interface properties. (3) Results revealed that while both modification methods can improve the chemical activity of the surface of PBO fibers, the La salt modification is more effective. The friction coefficient of all composites decreases with the increase of sliding velocity and load at two temperatures, and the specific wear rate is increases. Contrary to the situation in the 130 °C environment, the wear resistance of the unmodified composite in the 260 °C environment is greatly affected by the sliding velocity and load, while the modified composites are less affected. Under the same test parameters, the PBO–La/PI composite has the lowest specific wear rate and friction coefficient, and (4) La salt modification is a more effective approach to improve the properties of antifriction and wear resistance of PI composite than APTES modification in high ambient temperatures.

The Mechanical Properties and Friction and Wear Behavior of C/C-SIC

2010 ◽  
Author(s):  
Gao Wen ◽  
Chongsheng Long ◽  
Tang Rui ◽  
Jiping Wang
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Friction And Wear ◽  
Wear Behavior ◽  
Normal Load ◽  
Carbon Matrix ◽  
Specific Wear Rate ◽  
Sliding Speed ◽  
Wear Rates ◽  
Sic Composites

Carbon fiber reinforced carbon-silicon carbide composites (C/C-SiC) were prepared by chemical volume infiltration (CVI) method and reaction melt infiltration (RMI) technique of silicon liquid to carbon reinforce carbon matrix composites. The friction and wear behaviors of C/C-SiC composites at various loads and sliding speeds were investigated by MRH-3 block-on-ring tribometer at room temperature under water lubricating conditions. Furthermore, the morphologies, phase of the worn surface and the debris were observed, examined and analyzed by scanning electron microscopy (SEM) and energy-dispersive X-ray microanalysis (EDAX) respectively. Experimental results showed that the C/C-SiC composites had a better wear resistence, and the friction coefficient under water lubricated conditions is about 0.02–0.06. The influence of sliding speed on the friction coefficients and the specific wear rate of C/C-SiC is more obvious than that of normal load when the load is less than 200N (inclueded200N). The friction coefficient and the specific wear rate of C/C-SiC decreased as the sliding velocity increased. At the sliding speed higher than 2m/s, the friction coefficient is less than 0.02. The specific wear rates is at a low level about (2×10−7mm3/Nm–5×10−8mm3/Nm).

Friction and Wear Properties of PTFE Composites Against 6061-T6 Aluminum Alloy Under Hydrogen Atmosphere

2011 ◽  
Author(s):  
Y. Sakano ◽  
T. Iwai ◽  
Y. Shoukaku
Keyword(s):  
Aluminum Alloy ◽  
Wear Rate ◽  
Friction And Wear ◽  
Wear Track ◽  
Hydrogen Atmosphere ◽  
Specific Wear Rate ◽  
Wear Properties ◽  
Friction And Wear Properties ◽  
Ptfe Composites ◽  
Alloy 6061

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.

scholarly journals Friction and Wear Performance of Staple Carbon Fabric-Reinforced Composites: Effects of Surface Topography

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 141 ◽  
Author(s):  
Chang-Mou Wu ◽  
Yi-Ching Cheng ◽  
Wen-You Lai ◽  
Po-Hsun Chen ◽  
Tzong-Der Way
Keyword(s):  
Wear Rate ◽  
Surface Topography ◽  
Tribological Properties ◽  
Friction And Wear ◽  
Applied Pressure ◽  
Specific Wear Rate ◽  
Test Machine ◽  
Carbon Fabric ◽  
Sliding Speed ◽  
Resin Impregnation

Here, staple carbon fiber fabric-reinforced polycarbonate (PC)- and epoxy (EP)-based composites with different impregnating resin levels were fabricated using a modified film stacking process. The effects of surface topographies and resin types on the tribological properties of stable carbon fabric composites (sCFC) were investigated. Friction and wear tests on the carbon composites were conducted under unlubricated sliding using a disk-on-disk wear test machine. Experimental results showed that the coefficient of friction (COF) of the sCFC was dominated by matrix type, followed by peak material portion (Smr1) values, and finalized with core height (Sk) values. The COF of composites decreased by increasing the sliding speed and applied pressure. This also relied on surface topography and temperature generated at the worn surface. However, the specific wear rate was strongly affected by resin impregnation. Partially-impregnated composites showed lower specific wear rate, whereas fully-impregnated composites showed a higher wear rate. This substantially increased by increasing the sliding speed and applied pressure. Scanning electron microscopy observations of the worn surfaces revealed that the primary wear mechanisms were abrasion, adhesion, and fatigue for PC-based composites. For EP-based composites, this was primarily abrasion and fatigue. Results proved that partially-impregnated composites exhibited better tribological properties under severe conditions.

Friction and Wear of MoS2 Films on Laser Textured Steel Surfaces

2008 ◽  
Author(s):  
Lev Rapoport ◽  
Alexey Moshkovich ◽  
Vladislav Perfilyev ◽  
Igor Lapsker ◽  
Gregory Halperin ◽  
...  
Keyword(s):  
Friction And Wear ◽  
Solid Lubricant ◽  
Surface Texturing ◽  
Laser Surface ◽  
Laser Surface Texturing ◽  
Wear Life ◽  
Lubricant Films ◽  
Mos2 Film ◽  
Steel Surfaces ◽  
Solid Lubricant Films

Incorporation of solid lubricant into micro-reservoirs produced by Laser Surface Texturing (LST) and its effect on the tribological properties of surfaces under dry friction is studied. The density of the dimple reservoirs and the height of the bulges around them are investigated in terms of the longevity of solid lubricant films burnished on LST steel surfaces. Friction tests were performed using a ball-on-flat device. Optimum density (40–50%) of the dimples is revealed. It is shown that the adhesion of solid lubricant in the space between the dimples is provided by mechanical engagement of particles in the rough surface and by smearing the solid lubricant around the dimples. Best results are obtained with the surfaces that were lapped to half of the height of bulges. Long wear life of burnished film on LST steel surfaces is apparently provided by preservation of thin MoS2 film around the bulges and by supply of solid lubricant from the dimples to the surface. The effect of repeated burnishing on wear life of solid lubricant films was studied. Repeating burnishing leading to increasing the density of solid lubricant films increases the wear life.

Friction and Wear Behaviors of Si3N4 Sliding against M50 Bearing Steel in Vacuum

2010 ◽  
Vol 97-101 ◽  
pp. 1681-1684 ◽  
Author(s):  
Yong Xing Tong ◽  
Li Qin Wang ◽  
Le Gu
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Critical Load ◽  
Friction And Wear ◽  
Applied Load ◽  
High Vacuum ◽  
Optical Microscope ◽  
Bearing Steel ◽  
Specific Wear Rate ◽  
Si3n4 Ceramics

The friction and wear performances of Si3N4 ceramics sliding against bearing steel and to find optimal operating condition against M50 bearing steel couples under high vacuum surroundings were investigated. The tests were studied on the ball-disk machine under different loads and steady sliding velocity. The worn surfaces of tested samples were examined using optical microscope，SEM and XPS. The results showed that the friction coefficient of Si3N4 was decided by the applied load, the critical load of Si3N4’ friction coefficient was 10N applied load; The critical load of Si3N4’ specific wear rate was 5N applied load, the specific wear rate of Si3N4 drop rapidly as the applied load exceeded the critical load; The dominant wear mechanisms of Si3N4 ceramics were adhesion wear, brittle facture and furrow wear in vacuum.

Experimental Study on Friction and Wear Behaviors of Ball Bearings under Gas Lubricated Conditions

2014 ◽  
Vol 66 (3) ◽  
Author(s):  
Mohd Fadzli Abdollah ◽  
Mohd Afiq Azfar Mazlan ◽  
Hilmi Amiruddin ◽  
Noreffendy Tamaldin
Keyword(s):  
Wear Rate ◽  
Coefficient Of Friction ◽  
Friction And Wear ◽  
Applied Load ◽  
Specific Wear Rate ◽  
Design Parameters ◽  
Ball Bearings ◽  
Sliding Speed ◽  
Air Lubrication ◽  
Sliding Distance

Friction and wear behaviors of ball bearings made from carbon-chrome steel were experimentally simulated using a modified ball-on-disc tribometer. The test was performed over a broad range of applied loads (W), sliding velocities (v) and sliding distances (L) under gas lubricated conditions using a Taguchi method. The results found that gas blown to the sliding surfaces in air effectively reduced the coefficient of friction as compared with the air lubrication at higher applied load, sliding speed and sliding distance. In addition, a specific wear rate is constant throughout the tests under gas lubricated conditions. However, under air lubrication, the specific wear rate decreases with increasing applied load, sliding speed and sliding distance. By using the optimal design parameters, a confirmation test successfully verify the N2-gas lubrication reduced average coefficient of friction and simultaneously improved wear resistance about 24% and 50%, respectively. This is in accordance with a significant reduction of wear scar diameter and smoother worn surface on a ball.

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