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.

scholarly journals Fabrication and Tribological Properties of Copper Matrix Solid Self-Lubricant Composites Reinforced with Ni/NbSe2 Composites

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1854
Author(s):  
Fei-xia Zhang ◽  
Yan-qiu Chu ◽  
Chang-sheng Li
Keyword(s):  
Powder Metallurgy ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Friction And Wear ◽  
Copper Matrix ◽  
Wear Properties ◽  
Disk Friction ◽  
Friction Reducing ◽  
Properties Of Composites

This paper presents a facile and effective method for preparing Ni/NbSe2 composites in order to improve the wettability of NbSe2 and copper matrix, which is helpful in enhancing the friction-reducing and anti-wear properties of copper-based composites. The powder metallurgy (P/M) technique was used to fabricate copper-based composites with different weight fractions of Ni/NbSe2, and tribological properties of composites were evaluated by using a ball-on-disk friction-and-wear tester. Results indicated that tribological properties of copper-based composites were improved by the addition of Ni/NbSe2. In particular, copper-based composites containing 15 wt.% Ni/NbSe2 showed the lowest friction coefficient (0.16) and wear rate (4.1 × 10−5 mm3·N−1·m−1) among all composites.

scholarly journals Effect of Self-Generated Transfer Layer on the Tribological Properties of PTFE Composites Sliding against Steel

Coatings ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 399 ◽  
Author(s):  
Ting Xie ◽  
Shihao Feng ◽  
Yongheng Qi ◽  
Ailong Cui
Keyword(s):  
Friction Coefficient ◽  
Layer Thickness ◽  
Tribological Properties ◽  
Normal Load ◽  
Wear Test ◽  
Wear Volume ◽  
Functional Requirements ◽  
Transfer Layer ◽  
Sliding Speed ◽  
Ptfe Composites

Coatings are normally employed to meet some functional requirements. There is a kind of self-generated coating during use, such as the transfer layer during sliding, which may greatly affect the tribological behavior. Although the transfer layer has aroused much attention recently, the formation of the transfer layer closely depends on the service conditions, which need to be further studied. In this paper, the effects of sliding speed, normal load, and duration of wear test on the transfer layer thickness during friction of Ni/PTFE (Polytetrafluoroethylene) composites were experimentally investigated. The formation mechanism of transfer layer and the relationships between tribological properties and transfer layer thickness were analyzed in detail. It was found that the transfer layer thickness increased with increases of sliding speed and normal load; and after a period of wear test, the transfer layer thickness remained stable. The transfer layer thickness correlates linearly with the friction coefficient and wear volume of the PTFE composites. With the increase of the transfer layer thickness, the friction coefficient decreased, while the wear volume increased, which means that a uniform, thin, and stable transfer layer is beneficial for the reduction of friction and wear of the polymeric composites.

Mechanical and Tribological Properties of Multi-Element CrTiAlN Coatings for Dry Cutting Deposited by Magnetron Sputtering Technologies

2010 ◽  
Vol 34-35 ◽  
pp. 610-615
Author(s):  
Zhi Hai Cai ◽  
Ping Zhang ◽  
Jia Wu He
Keyword(s):  
Friction Coefficient ◽  
Magnetron Sputtering ◽  
Tribological Properties ◽  
Composite Films ◽  
Experimental Results ◽  
Wear Volume ◽  
X Ray Diffraction ◽  
Dry Cutting ◽  
Mechanical And Tribological Properties ◽  
Section Structure

Multi-element CrTiAlN coatings are deposited onto YT14 cemented carbide milling cutter by magnetron sputtering in an Ar+N2 mixture. The nano-indenter, scanning electron microscopy, X-ray diffraction and Rockwell indentations were used to investigate the mechanical property, microstructure and adhesion strength of CrTiAlN coatings. And the tribological properties and dry cutting performance of the CrTiAlN coatings were compared with TiN and TiAlN coatings. The experimental results showed that the phase structures of the composite films include Cr, CrN, Cr2N and TiN phases. And the surface crystal grain of CrTiAlN coatings is relative small and the section structure of CrTiAlN coatings was columns crystal structure. It showed better for CrTiAlN coatings on nano-hardness and adhesion compared with TiN and TiAlN coatings. And the friction coefficient of above three kind coatings was about 0.12-0.15. The friction coefficient and wear volume of CrTiAlN coatings appeared lowest among these three kind coatings. Dry cutting experimental results showed that the sequence of cutting life for these coated tools were CrTiAlN＞TiAlN＞TiN.

Effect of Waste-Derived Calcium Sulfate Additions on the Tribological Properties of Sintered Steel-Based Material

2019 ◽  
Vol 798 ◽  
pp. 146-151
Author(s):  
Chiraporn Auechalitanukul ◽  
Ryan McCuiston ◽  
Ton Sukantowong ◽  
Wachira Wachirapanee ◽  
Treepak Surmpakdeekul
Keyword(s):  
Friction Coefficient ◽  
Tribological Properties ◽  
Calcium Sulfate ◽  
High Carbon Steel ◽  
Slip Casting ◽  
Weight Percent ◽  
Wear Volume ◽  
Powder Metallurgy Method ◽  
Kinetic Friction ◽  
Steel Material

This study examined the effect of waste-derived calcium sulfate additions (2 to 8 weight percent) on the tribological properties of a sintered high-carbon steel material, commonly used for frictional applications. The calcium sulfate powder was obtained by crushing and subsequent calcination of waste plaster molds previously used for slip casting of ceramics. Samples were made using the powder metallurgy method. Powder mixtures were uniaxially die compacted and sintered at 1,100°C for 30 minutes in a reducing atmosphere. It was found that the density of the samples decreased with increased amounts of calcium sulfate. This was due to the lower theoretical density of the calcium sulfate as well as volumetric expansion of the samples. Ball-on-disc tribological testing was performed at room temperature. The addition of calcium sulfate resulted in an increase of the kinetic friction coefficient. The measured wear volume was slightly reduced with the addition of calcium sulfate less than 6 weight percent, beyond which the wear increased. The hardness of the samples was reduced with the addition of calcium sulfate. Increased calcium sulfate content decreased the sample deformation resistance while increasing the kinetic friction coefficient and the wear. This was likely due to the microstructural changes of the samples, which will be discussed.

Effects of Friction Load and Ultrasonic Vibration on the Tribological Properties of Al2O3/Al2O3 Ceramic Friction Pairs under Liquid Paraffin Lubrication

2013 ◽  
Vol 652-654 ◽  
pp. 1881-1885
Author(s):  
Xin Yu Dong ◽  
Yu Lin Qiao ◽  
Yan Zang ◽  
Qing Sheng Cui
Keyword(s):  
Friction Coefficient ◽  
Ultrasonic Vibration ◽  
Tribological Properties ◽  
Friction And Wear ◽  
Liquid Paraffin ◽  
Friction Reduction ◽  
Wear Volume ◽  
Oil Lubrication ◽  
Wear Properties ◽  
Load Range

The effects of friction load and ultrasonic vibration on friction reduction and anti-wear properties of Al2O3/Al2O3 ceramic frictional pairs under oil lubrication were investigated by a modified MFT-R4000 reciprocating friction and wear tester. The mechanism of friction reduction and anti-wear under ultrasonic vibration was discussed. The results showed that, the ultrasonic vibration could influence the friction reduction and anti-wear properties of Al2O3/Al2O3 ceramic friction pairs due to it could reduce the stress between the friction pairs and destroy the oil film on the surface of samples. When the friction frequency was 2Hz, the ultrasonic vibration could reduce the friction coefficient within experiment load range. When the loads were 70N, 80N, 90N and 100N, the average friction coefficient were reduced by 16.1%, 14.5%, 9.7% and 2.6%,and wear volume of frictional pairs decreased 35%、32%、31% and 12%.

The Effect of TiO2 on the Mechanical and Tribological Properties of PA66 Nanocomposites

2011 ◽  
Vol 284-286 ◽  
pp. 513-516 ◽  
Author(s):  
Jun Bao
Keyword(s):  
Plastic Deformation ◽  
Friction Coefficient ◽  
Tribological Properties ◽  
Inorganic Nanoparticles ◽  
Wear Volume ◽  
Volume Loss ◽  
Screw Extruder ◽  
Nano Tio2 ◽  
Mechanical And Tribological Properties ◽  
Twin Screw

PA66 nanocomposites with various contents of TiO2 were prepared by twin-screw extruder in order to study the influence of inorganic nanoparticles on tribological properties of PA66melt-intercalation method. The effects of content of nanoparticles and load on friction coefficient and wear volume loss were investigated, respectively. The tensile properties of PA66/TiO2 nanocomposites were greatly improved. The tribological behaviors of the PA66/TiO2 nanocomposites against steel ring were evaluated on a block-on-ring type (M-2000) wear tester. Nano TiO2 at 1vol.% was effective for improving the tribological properties of neat PA66, because the nano TiO2 at the low content may act as the reinforcing element to bore load and thus decrease the plastic deformation.

Effects of Ultrasonic Vibration on Tribological Properties of GCr15/45# Steel Frictional Pairs in Lubricated Sliding Conditions under Various Friction Speed

2011 ◽  
Vol 338 ◽  
pp. 599-602 ◽  
Author(s):  
Yu Lin Qiao ◽  
Shan Lin Yang ◽  
Yan Zang ◽  
Xin Yu Dong
Keyword(s):  
Friction Coefficient ◽  
Ultrasonic Vibration ◽  
Tribological Properties ◽  
Friction And Wear ◽  
Friction Reduction ◽  
Wear Volume ◽  
Oil Lubrication ◽  
Wear Properties ◽  
Oil Film ◽  
Lubricated Sliding

The effects of friction speed and ultrasonic vibration on friction reduction and anti-wear properties of GCr15/45# steel frictional pairs under oil lubrication were investigated by a modified MFT-R4000 reciprocating friction and wear tester. The mechanism of friction reduction and anti-wear under ultrasonic vibration was discussed. The results showed that, the ultrasonic vibration could influence the friction reduction and anti-wear properties of frictional pairs due to it could reduce the stress between the friction pairs and destroy the oil film on the surface of samples. When the friction frequency was 2Hz，ultrasonic vibration would reduce the friction coefficient and wear volume of the frictional pairs. When the load was 40N, the friction coefficient and wear volume of the frictional pairs attained under ultrasonic vibration decreased 8% and 44% respectively. However, ultrasonic vibration would increase the friction coefficient and wear volume when the friction frequency was 5Hz. When the load was 30N, friction coefficient and wear volume of frictional pairs increased 11% and 74% than that without ultrasonic vibration respectively.

scholarly journals Effect of the detonation-spraying mode on the tribological properties of NiCr-Al2O3 coatings

2021 ◽  
Vol 5 (1) ◽  
pp. 39-44
Author(s):  
B.K. Rakhadilov ◽  
D.B. Buitkenov ◽  
E. Kabdykenova ◽  
Zh.B. Sagdoldina ◽  
L.G. Zhurerova
Keyword(s):  
Wear Resistance ◽  
Phase Composition ◽  
Tribological Properties ◽  
Volume Fraction ◽  
Oxygen Mixture ◽  
High Wear Resistance ◽  
Wear Volume ◽  
Detonation Spraying ◽  
Filling Volume ◽  
Study Results

The article presents the study results of detonation spraying parameters on the phase composition and tribological properties of NiCr-Al2O3 powder coatings. The spraying was carried out at a ratio of the acetylene-oxygen mixture O2 /C2H2=1.856. The detonation barrel filling volume with an explosive gas mixture varied from 30% to 68%. It is determined that the phase composition of the NiCr-Al2O3 coatings varies depending on the degree of detonation barrel filling. With an increase in the detonation barrel’s filling volume, the intensity of the NiCr diffraction peaks is decreased, and the intensity of the a-Al2O3 reflexes is increased, which indicates an increase in the content of the Al2O3 phase. When low filling volume, there is determined a low coating density and uneven roughness. The tribological test results showed that with an increase in the detonation barrel filling volume, there is a decrease in the wear volume, which confirms the increase in the coatings wear resistance. Determined that the lowest friction coefficient was recorded in the sample obtained at the barrel filling volume 68%. The coatings’ high wear resistance is associated with an increase in the alpha phase volume fraction of a-Al2O3 and coatings density.

scholarly journals Face Grinding Surface Quality of High Volume Fraction SiCp/Al Composite Materials

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Xu Zhao ◽  
Yadong Gong ◽  
Guiqiang Liang ◽  
Ming Cai ◽  
Bing Han
Keyword(s):  
Friction Coefficient ◽  
Surface Morphology ◽  
Surface Quality ◽  
Volume Fraction ◽  
High Volume ◽  
Spindle Speed ◽  
High Volume Fraction ◽  
Machining Parameters ◽  
Al Composite

AbstractThe existing research on SiCp/Al composite machining mainly focuses on the machining parameters or surface morphology. However, the surface quality of SiCp/Al composites with a high volume fraction has not been extensively studied. In this study, 32 SiCp/Al specimens with a high volume fraction were prepared and their machining parameters measured. The surface quality of the specimens was then tested and the effect of the grinding parameters on the surface quality was analyzed. The grinding quality of the composite specimens was comprehensively analyzed taking the grinding force, friction coefficient, and roughness parameters as the evaluation standards. The best grinding parameters were obtained by analyzing the surface morphology. The results show that, a higher spindle speed should be chosen to obtain a better surface quality. The final surface quality is related to the friction coefficient, surface roughness, and fragmentation degree as well as the quantity and distribution of the defects. Lower feeding amount, lower grinding depth and appropriately higher spindle speed should be chosen to obtain better surface quality. Lower feeding amount, higher grinding depth and spindle speed should be chosen to balance grind efficiently and surface quality. This study proposes a systematic evaluation method, which can be used to guide the machining of SiCp/Al composites with a high volume fraction.

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.

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