Research on Tribological Properties of Micro-Vehicle Clutch’s Friction Material

2009 ◽  
Vol 87-88 ◽  
pp. 58-63
Author(s):  
Jun Cheng Lv ◽  
Yi Min Mo ◽  
Li Na Pan
Keyword(s):  
Friction Coefficient ◽  
Working Conditions ◽  
Tribological Properties ◽  
Line Graph ◽  
Friction Material ◽  
Wear Rates ◽  
Test Standards ◽  
Sample Test ◽  
Different Temperatures ◽  
National Test

To explore the substantial cause of the early abnormal wear of micro-vehicle clutch’s friction material, the sample test aimed at studying the tribological properties of micro-vehicle clutch’s friction material is designed, according to GB/5763-98 national test standards. The broken line graph of samples’ friction coefficient on and wear rates in different working conditions are obtained. There are two types of working conditions. One is the same line speed and different working loads of samples, and the other is the same working load and different line speeds. Combined Scanning Electron Microscopy (SEM)’s observation with tribological principle, the sample test result is analyzed, thus obtaining the changing rules of the materials’ friction coefficient and wear rates at different temperatures, working loads and line speeds.

The Research on Wear Mechanism of Micro-Automobile Clutch Friction Material

2010 ◽  
Vol 426-427 ◽  
pp. 653-657 ◽  
Author(s):  
Jun Cheng Lv ◽  
Yi Min Mo ◽  
L. Pan
Keyword(s):  
Abrasive Wear ◽  
Friction Surface ◽  
Adhesive Wear ◽  
Friction Material ◽  
Final Conclusion ◽  
Severe Wear ◽  
Test Standards ◽  
Mild Wear ◽  
Sample Test ◽  
National Test

According to the national test standards for constant speed friction tester :GB/5763-98, the sample test is designed which suits for the study of the micro-automobile clutch friction material’s properties, and the experiment data has been analyzed, and also using X-ray diffraction and Scanning electron microscopy(SEM) to analyze the friction coefficient of friction material, changes in wear quality and the formation of friction work surface layer, the final conclusion has been made that the micro-automobile clutch sliding wear consist of mild wear and severe wear; The friction surface of mild wear is relatively rough, while the friction surface of severe wear is relatively smooth or with obvious noise; mild wear mostly appears as oxidation wear and abrasive wear and normally with the adhesive wear together, while severe wear is mostly induced by severe plastic deformation(serious delaminating wear) , and mostly appears as adhesive wear and abrasive wear.

Study on Space Copper-Based Powder Metallurgy Friction Material and its Tribological Properties

2011 ◽  
Vol 284-286 ◽  
pp. 479-487 ◽  
Author(s):  
Ping Ping Yao ◽  
Ye Long Xiao ◽  
Jun Wang Deng
Keyword(s):  
Powder Metallurgy ◽  
Friction Coefficient ◽  
Mass Loss ◽  
Tribological Properties ◽  
High Vacuum ◽  
Atmospheric Condition ◽  
Friction Material ◽  
Vacuum Condition ◽  
Essential Difference ◽  
New Compounds

The microstructure and tribological properties of space copper-based friction material fabricated by Powder Metallurgy technology were studied using optical metallographic microscope and MM-1000-type tribo-tester, respectively. The results are shown as follows: The lubricant MoS2 was resolved during sintering, resulting in the loss of S element. MoS2 and its resolvents reacted with other components into some new compounds which contribute to the tribological properties of friction material. The lubrication mechanism of these new compounds showed essential difference in comparison to that for MoS2; the friction coefficient was higher under atmospheric condition than that under vacuum conditions, but almost the same under low and high vacuum conditions. It decreased under both atmospheric and low vacuum conditions with the increase of load. The environmental temperature had insignificant effect on the friction coefficient; under atmospheric condition as load increased, the mass loss of material decreased linearly, then increased. With regard to low vacuum condition as load increased, the mass loss of material increased, then decreased; the stable coefficient of friction material under vacuum condition was higher than that under atmospheric condition.

Preparation and Tribological Behavior of Self-Lubrication Composites Ni-W-Cr-Fe-Cu-MoS2-Graphite at Elevated Temperature

2013 ◽  
Vol 668 ◽  
pp. 3-8 ◽  
Author(s):  
Jian Rong Sun ◽  
Chang Sheng Li ◽  
Hua Tang ◽  
Zhi Cheng Guo ◽  
Jin Ying Zi Liu
Keyword(s):  
Tensile Strength ◽  
Elevated Temperature ◽  
Powder Metallurgy ◽  
Friction Coefficient ◽  
Tribological Properties ◽  
Room Temperature ◽  
Tribological Behavior ◽  
Strengthening Effect ◽  
Wear Rates ◽  
Increasing Temperature

The composites of Ni-W-Cr-Fe-Cu-MoS2-Graphite with nano-MoS2 were prepared by powder metallurgy. Its tribological properties were investigated using the UTM-2 Nano+Micro Tribometer from room temperature to 600°C. The effects of amount of MoS2 and Ni-W-Cr prealloy powder, load, and temperature on the tribological properties were investigated and discussed. The results indicated that the addition of 43~45wt.% Ni-W-Cr prealloy powder had a strengthening effect on the hardness, anti-press and tensile strength. The tensile strength of the composite decreases with the addition of Nano-MoS2 and graphite, and the friction coefficient decrease with increase of the additives over the wide temperature range of 25°C∼600°C. The friction coefficients and wear rates of the composites reach the optimization value at 2.5wt.% MoS2,While its wear rates increase with the increasing temperature and load.

Effect of Surface Modified Foamed Fe Powder on Tribological Properties of Semi-Metallic Friction Material

2013 ◽  
Vol 668 ◽  
pp. 75-79
Author(s):  
Yang Cao ◽  
Yuan Kang Zhou ◽  
Jian Yu Wei ◽  
Tao Yue Yang ◽  
Hua Wei Nie
Keyword(s):  
High Temperature ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Coupling Agent ◽  
Silane Coupling Agent ◽  
Hydrophobic Surface ◽  
Friction Material ◽  
Fe Powder ◽  
Silane Coupling

The silane coupling agent KH550 is used to modify foamed Fe powder(FFP) surface for obtain the hydrophobic surface, which is the very important component in semi-metallic friction material. It can improve high temperature bonding force between FFP and phenolic resin, further improve friction coefficient stableness of friction material and abrasion resistance. The modification effect of FFP is characterized by IR, and the tribological properties is characterized by XD-MSM constant speed friction test machine, the surface topography is characterized by SEM. The results indicate that FFP has been bonded to silane coupling agent, and formed hydrophobic surface what has the alkyl group. The changing of friction coefficient has reduced 23%, the average wear rate has declined 28.6%,and the wear rate has declined 32% at 350 °C after the friction material with modified FFP compare with the one with original FFP. And those changing are all because of the fact that the FFP modified by KH550 is difficult to peel off during the high temperature.

Tribological and Mechanical Properties of Materials for Friction Pairs Used to Space Docking

2012 ◽  
Vol 538-541 ◽  
pp. 1929-1934 ◽  
Author(s):  
Ping Ping Yao ◽  
Ye Long Xiao ◽  
Hai Bing Zhou ◽  
Zong Xiang Jin
Keyword(s):  
Mechanical Properties ◽  
Friction Coefficient ◽  
Tribological Properties ◽  
Friction Material ◽  
Friction Torque ◽  
Operation Conditions ◽  
Mechanical Properties Of Materials ◽  
Properties Of Materials ◽  
Counterpart Material

The microstructures and tribological properties of materials for friction pairs used to space docking were investigated by optical metallographic microscope and a special home-made tribo-tester, respectively. The results demonstrate that friction material appears homogeneous and compact microstructure. Counterpart material presents temper sorbite which keeps martensite morphology and residues a small amount of blocky undissolved ferrite; the porosity of friction material is about 3.7%. Materials for space docking show favorable rigidity; during running-in, friction torque of friction pairs can be enhanced obviously; under different operation conditions, friction pairs for space docking possesses different friction coefficient.

scholarly journals Frictional Behaviour of Composite Anodized Layers on Aluminium Alloys

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3747
Author(s):  
Radomir Atraszkiewicz ◽  
Marcin Makówka ◽  
Łukasz Kołodziejczyk ◽  
Bartłomiej Januszewicz ◽  
Jan Sucharkiewicz
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Friction Coefficients ◽  
Friction Forces ◽  
Sic Nanoparticles ◽  
Wear Rates ◽  
Three Samples ◽  
Micro Arc Oxidation ◽  
Embedded Nanoparticles

Three variants of the micro arc oxidation (MAO) technique have been used to treat a 2017A alloy surface. The first variant was a pure anodized layer, the second an anodized layer with SiC embedded nanoparticles and the third an anodized layer with Si3N4 nanoparticles. Tribological tests were performed for all variants, on three samples for every case. Friction coefficients and wear rates were calculated on the basis of experiments. The pure anodized layer manifested friction coefficient values within the range of 0.48 ÷ 0.52 and a wear rate in the range ~10−15 m3N−1m−1. SiC nanoparticles improved the tribological properties of the layer, as indicated by a reduction of the friction coefficient values to the range of 0.20 ÷ 0.26 with preserved very high resistance against wear (wear rate ~10−15 m3N−1m−1). Si3N4 particles embedded in anodized layer deteriorated the tribological properties, with a reduction in the resistance against fatigue and wear, intensification of friction forces and a change in the nature of friction contact behavior to more abrasive-like nature (friction coefficients ranging from 0.4 to 0.6 and wear rates ~10−14 m3N−1m−1).

Influence of carbon nanotubes on the properties of friction composite materials

2019 ◽  
Vol 54 (16) ◽  
pp. 2101-2111
Author(s):  
Emad F EL-kashif ◽  
Shaimaa A Esmail ◽  
Omayma AM Elkady ◽  
BS Azzam ◽  
Ali A Khattab
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Friction Coefficient ◽  
Tribological Properties ◽  
Smart Materials ◽  
Arc Discharge ◽  
Weight Ratio ◽  
Friction Material ◽  
Operating Conditions ◽  
Friction Materials

Carbon nanotubes have a lot of applications in mechanical fields. This is because nanomaterials have many superior mechanical properties such as very high strength-to-weight ratio, high modulus-to-weight ratio, high corrosion resistance, and super intelligence properties, which make them as smart materials. One of these attractive applications is the use of carbon nanotubes in vehicle brake friction material. Therefore, the fabrication and testing processes of these nanomaterials should be performed carefully to evaluate their mechanical, tribological, and noise properties. In this paper, friction material mixed with carbon nanotubes have been fabricated with different carbon nanotube contents and the same fabrication parameters. The carbon nanotubes have been produced using the conventional submerged arc discharge technique. The produced friction materials have been cut into pieces with standard sizes and then tested mechanically and tribologically. The results of tests have illustrated that the addition of carbon nanotubes into the friction materials could improve their mechanical properties (hardness, strength, and modulus) and also could enhance their tribological properties (wear rate and friction coefficient). Moreover, the tests showed that the presence of carbon nanotubes in friction materials could reduce the noise, vibration of the friction materials, and reduce the temperature rise due to the effect of friction, which means that the carbon nanotubes could raise the thermal conductivity of friction material, while the friction coefficient has stayed within the allowable standard limits (0.35–0.45). Surface morphology shows that the presence of carbon nanotubes in the friction materials could help to avoid surface friction cracks or fins within the normal operating conditions. The good combination of mechanical and tribological properties was obtained at 0.5% carbon nanotubes.

Tribological Properties of Cu Based Friction Composites with In Situ Synthesized TiC Filler

2010 ◽  
Vol 160-162 ◽  
pp. 35-47 ◽  
Author(s):  
Bai Ming Chen ◽  
Zheng Yu Zhang ◽  
Ming Xu Wang ◽  
Guo Cai Han ◽  
Liang An
Keyword(s):  
Powder Metallurgy ◽  
Friction Coefficient ◽  
Tribological Properties ◽  
Solid Lubricant ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wear Rates ◽  
Ti Content

The Cu based friction composites using graphite as solid lubricant with different weight rations of Ti, i.e. 8 wt.%, 12 wt.%, 16 wt.%, 20 wt.%, were sintered by powder metallurgy (P/M) method. The structure of the composites was characterized by X-ray diffraction (XRD) and the tribological properties was studied on block-on-ring tester. XRD results verified presence of TiC phase which was in-situ synthesized through reaction of Ti and graphite in the composites, and the content of TiC was increased with the increased Ti content. The in-situ synthesized TiC phase which was fine and distributed uniformly improved tribological properties of Cu based friction composites significantly. The hardness, wear rates and friction coefficient of composites were increased with increasing amount of in-situ synthesized TiC.

Tribological Properties of Spark Plasma Sintered NiCr–Cr2AlC Composites at Elevated Temperature

2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Xinliang Li ◽  
Hong Yin ◽  
Yu-Feng Li
Keyword(s):  
Friction Coefficient ◽  
Tribological Properties ◽  
Room Temperature ◽  
Solid State Reaction Method ◽  
Nicr Alloy ◽  
Wear Process ◽  
Wear Rates ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Alumina Ball

In this work, layered ternary Cr2AlC powders with high purity and a size of 0.5–1 μm were synthesized by solid-state reaction method. NiCr–Cr2AlC composites have been prepared by spark plasma sintering (SPS) process. The composites' tribological properties were evaluated against alumina ball under dry sliding condition from room temperature to 600 °C. Compared with unmodified NiCr alloy, Cr2AlC addition has an effect on reduction of friction coefficient of NiCr–Cr2AlC composites at the temperatures up to 400 °C. Especially, in comparison with NiCr alloy, the wear rates of NiCr–Cr2AlC composites significantly decrease from 10−4 mm3/(N·m) to 10−5–10−6 mm3/(N·m) from room temperature to 600 °C (except for 200 °C). The NiCr–20 wt % Cr2AlC composite exhibited excellent tribological properties with a friction coefficient of 0.3–0.4 and a wear rate of about 10−6 mm3/(N·m) from 400 °C to 600 °C. Through the analysis of scanning electron microscope (SEM) and X-ray photoelectron spectroscope (XPS), it is clarified that effective improvement of tribological properties of NiCr–Cr2AlC composites is attributed to a glaze layer consisting of NiO, Cr2O3, Al2O3, and NiCr2O4, which is formed by tribo-oxidation during wear process.

Effects of Hair Fibers on Braking Friction Materials

2011 ◽  
Vol 399-401 ◽  
pp. 1725-1728
Author(s):  
Yun Hai Ma ◽  
Bao Gang Wang ◽  
Sheng Long Shen ◽  
Xue Ying Geng ◽  
Hong Lei Jia ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Friction And Wear ◽  
Friction Material ◽  
Wear Property ◽  
Rockwell Hardness ◽  
Friction Materials ◽  
Wear Rates ◽  
Hair Fiber ◽  
The Stability ◽  
The Impact

In this experiment, the effects of hair fibers on friction and wear property, Rockwell hardness and impact strength of friction materials were examined. The results showed that friction coefficient increases and stabilizes and specific wear rates were decrease as the hair fibers were filled and, particularly, 1% of the hair fiber content had a significant effect in the friction material. As temperature was changed, the stability of the friction coefficient of friction materials can be improved, the Rockwell hardness decrease and the impact strengths increase by way of increasing the content of hair fibers. The worn surfaces of friction materials were examined by scanning electron microscopy and wear mechanisms were analyzed. So it’s a kind of quite good non-asbestos friction material.

Sign in / Sign up

Export Citation Format

Share Document