scholarly journals Graphene as a nanofiller for enhancing the tribological properties and thermal conductivity of base grease

RSC Advances ◽  
2019 ◽  
Vol 9 (72) ◽  
pp. 42481-42488
Author(s):  
Hui Fu ◽  
Guoping Yan ◽  
Meng Li ◽  
Hao Wang ◽  
Yapeng Chen ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Friction Coefficient ◽  
Tribological Properties ◽  
Friction Surface ◽  
Base Grease

The addition of graphene-reinforced grease to the mechanical friction surface can effectively reduce the friction coefficient and accelerate heat transportation.

Tribological Properties and Thermal Conductivity of Si3 N4 / Si3N4-BN Alternate Layered Composites

2006 ◽  
Vol 317-318 ◽  
pp. 363-368
Author(s):  
T. Hirao ◽  
Kiyoshi Hirao ◽  
Yukihiko Yamauchi
Keyword(s):  
Thermal Conductivity ◽  
Friction Coefficient ◽  
Tribological Properties ◽  
Hot Pressing ◽  
Layered Composite ◽  
Test Method ◽  
Ring Test ◽  
Layered Composites ◽  
Si3n4 Layer ◽  
Thermal Conductivities

Alternate layered composites of Si3N4 layers and layers of Si3N4 with 20 vol% of hBN (Si3N4-BN layers) were fabricated and their tribological properties and thermal conductivities were evaluated. The layered composites were fabricated by alternate stacking of a monolithic Si3N4 layer and a Si3N4-BN layer in the form of a green sheet, followed by hot-pressing or annealing. For comparison, Si3N4 and Si3N4 with 10% hBN were fabricated by hot-pressing powder mixtures. Tribological properties were evaluated on the side plane of the composites by a block-on-ring test method under a dry sliding condition and thermal conductivities were evaluated. The layered composites were found to have lower friction coefficients and higher wear resistance than to simple composites. Moreover, for the layered composite with an aligned β-Si3N4, the friction coefficient on the plane composed of faceted hexagonal grains was lower. The layered composite with an aligned β-Si3N4 in the Si3N4 layer, fabricated by annealing for 72 h indicated both a low friction coefficient (0.28) and high thermal conductivity (130 W/mK).

Observation of Thermophysical and Tribological Properties of CNT Reinforced Si3N4

2009 ◽  
Vol 409 ◽  
pp. 354-357 ◽  
Author(s):  
Orsolya Koszor ◽  
Andre Lindemann ◽  
François Davin ◽  
Csaba Balázsi
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Silicon Nitride ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Reference Sample ◽  
Si3n4 Ceramic ◽  
Pronounced Difference

Thermophysical and tribological measurements have been performed on carbon nanotube added silicon nitride composites. Higher thermal conductivity values were observed in the case of the sample with CNT than for the reference sample. As was observed from tribological measurements, nanocomposite Si3N4 without carbon nanotubes shows a higher friction coefficient than carbon nanotube - Si3N4. The results of wear study indicate that the Si3N4 ball (used as static partner) was more damaged with MWCNTs addition nanocomposite than with pure Si3N4 ceramic. A pronounced difference was observed in the wear rate: there was a much higher wear for carbon nanotube - Si3N4 than for Si3N4 without MWCNTs.

Surface Texturing Process by High Speed Ultrasonic Turning to Obtain Low Friction Surface

2020 ◽  
Author(s):  
Keisuke Hara ◽  
Hiromi Isobe
Keyword(s):  
Friction Coefficient ◽  
Tribological Properties ◽  
Friction Surface ◽  
Radial Direction ◽  
Ultrasonic Transducer ◽  
Surface Texturing ◽  
Operating Efficiency ◽  
Textured Surface ◽  
Textured Surfaces ◽  
Low Friction

Abstract Tribological properties such as lubrication, friction and wear resistance are important to improve machine operating efficiency, machine performances and machine life. To improve tribological properties of sliding surface, scraping is available. Scraping fabricates many small depression on target surface evenly, the depression will function oil hole which promote lubrication of flat bearing surface. Many researchers have reported the surface texturing method which aim is similar to scraping. For example, the techniques fast tool servo turning with diamond insert tool and turn mill processing by dual spindle turning center were reported to fabricate periodically micro dimple. However, these techniques employ expensive high precision machine tools. This paper introduces a more cheaply and rapidly surface texturing technique which employs ultrasonic vibration turning to obtain low friction surface and improve tribological properties. In ultrasonic turning, cutting tool tip is vibrated in principal direction and radial direction simultaneously origin from poisons deformation of ultrasonic transducer. The radial direction tool vibration functions to squeeze workpiece surface in workpiece radial direction periodically, textured surface will be obtained. The results of ultrasonic turning experiments, textured surfaces were obtained. In order to evaluate the tribological performance of the turned surface, friction coefficient between stainless steel pin and turned surface were measured under oil dipping condition. It was confirmed that friction coefficient of ultrasonic turned surface is drastically reduced compared with ordinary turned surface. And proposed technique is available to perform surface texturing for several materials.

Experimental study on the effect of surface texture on tribological properties of nanodiamond films under water lubrication

2021 ◽  
pp. 135065012110334
Author(s):  
Ying Yan ◽  
Xuelin Lei ◽  
Yun He
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Surface Texture ◽  
Diamond Film ◽  
Diamond Films ◽  
Nanocrystalline Diamond ◽  
Water Contact ◽  
Texture Density ◽  
Short Run

The effect of nanoscale surface texture on the frictional and wear performances of nanocrystalline diamond films under water-lubricating conditions were comparatively investigated using a reciprocating ball-on-flat tribometer. Although the untreated nanocrystalline diamond film shows a stable frictional state with an average friction coefficient of 0.26, the subsequent textured films show a beneficial effect on rapidly reducing the friction coefficient, which decreased to a stable value of 0.1. Furthermore, compared with the nanocrystalline diamond coating, the textured films showed a large decreasing rate of the corresponding ball wear rate from 4.16 × 10−3 to 1.15 × 10−3 mm3/N/m. This is due to the fact that the hydrodynamic fluid film composed of water and debris can provide a good lubrication environment, so the entire friction process has reached the state of fluid lubrication. Meanwhile, the surface texture can greatly improve the hydrophilicity of the diamond films, and as the texture density increases, the water contact angle decreases from 94.75° of the nanocrystalline diamond film to 78.5° of the textured films. The proper textured diamond film (NCD90) exhibits superior tribological properties among all tested diamond films, such as short run-in period, low coefficient of friction, and wear rate.

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.

Improvement of the thermal conductivity and tribological properties of polyethylene by incorporating functionalized boron nitride nanosheets

2022 ◽  
Vol 165 ◽  
pp. 107277
Author(s):  
Md Golam Rasul ◽  
Alper Kiziltas ◽  
Md Shafkat Bin Hoque ◽  
Arnob Banik ◽  
Patrick E. Hopkins ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Boron Nitride ◽  
Tribological Properties ◽  
Boron Nitride Nanosheets

Comparison in Tribological Properties of YBa2Cu3OX/Ag and Bi2Sr2CaCu2OX/Ag Self-Lubricating Composites

2011 ◽  
Vol 291-294 ◽  
pp. 34-40
Author(s):  
Hua Tang ◽  
Wen Jing Li ◽  
Chang Sheng Li
Keyword(s):  
Friction Coefficient ◽  
Tribological Properties ◽  
Room Temperature ◽  
Superconducting Transition ◽  
Friction Test ◽  
Average Value ◽  
Structure And Morphology ◽  
Disk Friction ◽  
Pin On Disk ◽  
Self Lubricating Composites

The YBa2Cu3Ox/Ag and Bi2Sr2CaCu2Ox/Ag self-lubricating composites were prepared using powder metallurgic method. The crystal structure and morphology of the as-synthesized samples were characterized by XRD and SEM. The YBa2Cu3Ox/Ag and Bi2Sr2CaCu2Ox/Ag self-lubricating composites were found to compose of superconductor phase and Ag phase. The tribological properties from ultra-low temperature to room temperature of the composites were studied by pin-on-disk friction test. It was found that the friction coefficients of pure YBa2Cu3Ox(YBCO) and Bi2Sr2CaCu2Ox(BSCCO) were both dropped abruptly when the temperature cooled below the superconducting transition temperature. At room temperature, the friction coefficient of pure YBa2Cu3Oxis 0.68~0.95, when mixing 15wt% Ag, the friction coefficient of the sample decreased to the lowest value 0.11. The friction coefficient of pure Bi2Sr2CaCu2Ox is 0.15~0.17, When Ag content reach 10wt%, the coefficient was lowest (average value is 0.13). The addition of appropriate amount of Ag obviously improve the tribological property of YBCO, while only slightly meliorate that of BSCO. On the other hand, the YBCO/Ag composites exhibit better tribological properties than BSCCO/Ag composites at higher load under the same experimental condition.

Tribological and electrical behavior of Cu-based composites with addition of Ti-doped NbSe2 nanoplatelets

2018 ◽  
Vol 70 (3) ◽  
pp. 560-567 ◽  
Author(s):  
Jian Feng Li ◽  
Qin Shi ◽  
HeJun Zhu ◽  
ChenYu Huang ◽  
Shuai Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Friction Coefficient ◽  
Electrical Properties ◽  
Tribological Properties ◽  
Solid State Reaction ◽  
Electrical Contact ◽  
Solid State Reaction Method ◽  
Content Type ◽  
Reaction Method

Purpose This paper aims to clarify the size and morphology of transition metal dichalcogenides has an impact on lubrication performance of Cu-based composites. This study is intended to show that Cu-based electrical contact materials containing Nb0.91Ti0.09Se2 have better electrical and tribological properties than those containing NbSe2. The tribological properties of Cu-based with different Ti-dopped NbSe2 content were also discussed. Design/methodology/approach The NbSe2 and Nb0.91Ti0.09Se2 particles were fabricated by thermal solid state reaction method. The powder metallurgy technique was used to fabricate composites with varying Nb0.91Ti0.09Se2 mass fraction. The phase composition of Cu-based composites was identified by X-ray diffraction, and the morphology of NbSe2/Nb0.91Ti0.09Se2 and the worn surface of composites were characterized by scanning electron microscopy and transmission electron microscopy. In addition, the tribological properties of composites were appraised using a ball-on-disk multi-functional tribometer. The data of friction coefficient and resistivity were analyzed and the corresponding conclusion was drawn. Findings In comparison with the pure copper, Cu-based composites containing Nb0.91Ti0.09Se2/NbSe2 had a lower friction coefficient, illustrating the Nb0.91Ti0.09Se2 with nano-size particles prepared in this work is a perfect choice for the fabrication of excellent electrical contact composites. Compared to composites with NbSe2, composites containing Nb0.91Ti0.09Se2 have better tribological and electrical properties. Research limitations/implications Because of the use of thermal solid state reaction method, the size of NbSe2 and Nb0.91Ti0.09Se2 is relatively large. Therefore, the fabrication of finer particles of Nb0.91Ti0.09Se2 is encouraged. Originality/value In this paper, the authors discuss the tribological and electrical properties of Cu-based composites, and the value of optimum obtained as Nb0.91Ti0.09Se2 content is 15 Wt.%.

scholarly journals An Investigation on Tribological Properties and Lubrication Mechanism of Graphite Nanoparticles as Vegetable Based Oil Additive

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Yu Su ◽  
Le Gong ◽  
Dandan Chen
Keyword(s):  
Friction Coefficient ◽  
Tribological Properties ◽  
Volume Fraction ◽  
Wear Volume ◽  
Lubrication Mechanism ◽  
Step Method ◽  
Antiwear Properties ◽  
Physical Deposition ◽  
Graphite Nanoparticles ◽  
Friction Reducing

This paper used graphite nanoparticles with the diameter of 35 and 80 nm and LB2000 vegetable based oil to prepare graphite oil-based nanofluids with different volume fractions by two-step method. The tribological properties of graphite nanoparticles as LB2000 vegetable based oil additive were investigated with a pin-on-disk friction and wear tester. Field emission scanning electron microscope (FE-SEM) and energy dispersive spectroscopy (EDS) were used to examine the morphology and the content of some typical elements of wear scar, respectively. Further, the lubrication mechanism of graphite nanoparticles was explored. It was found that graphite nanoparticles as vegetable based oil additive could remarkably improve friction-reducing and antiwear properties of pure oil. With the increase of volume fraction of graphite nanoparticles, the friction coefficient and the wear volume of disk decreased. At the same volume fraction, the smaller particles, the lower friction coefficient and wear volume. The main reason for the improvement in friction-reducing and antiwear properties of vegetable based oil using graphite nanoparticles was that graphite nanoparticles could form a physical deposition film on the friction surfaces.

The Influence of Surface Texture on Abrasive Wear

2019 ◽  
Vol 823 ◽  
pp. 33-40 ◽  
Author(s):  
Yu Tong Hu ◽  
Yong Yong He ◽  
Wei Wang
Keyword(s):  
Friction Coefficient ◽  
Femtosecond Laser ◽  
Abrasive Wear ◽  
White Light ◽  
Surface Texture ◽  
Friction Surface ◽  
Surface Texturing ◽  
Experimental Results ◽  
The Relationship ◽  
Main Factor

Friction happens everywhere. Abrasives generated in tribological process will result in secondary wear. Abrasive wear is a kind of rather common but harmful wear, which is the main reason for the damage of fifty-percent mechanical components by friction. Surface texturing is an effective method to improve the tribological and lubricating performance of tribo-pairs. In this paper, with different-size diamond particles added into the lubricant and a surface of the tribo-pairs textured by different parameters (diameter and depth) with femtosecond laser, the relationship between the surface texture and the abrasive wear was researched, and the influence of the texture on the abrasive wear was analyzed. The friction experiments were carried out on UMT3. The microstructures were tested and analyzed by SEM, microscope and White Light Interferometer respectively. The experimental results showed that the size of the surface texture, compared with that of abrasives, is the main factor which determines the friction coefficient. As the size of the surface texture is much bigger than that of the abrasives, the texture can accommodate the abrasives efficiently, and thus the friction coefficient is reduced efficiently.

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