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.

Analysis of tribological properties of graphite and aluminum composite materials prepared by powder metallurgy technique

2020 ◽  
Vol 10 (5) ◽  
pp. 663-670
Author(s):  
Zhigang Wang ◽  
Jun Li ◽  
Daquan Li
Keyword(s):  
Composite Materials ◽  
Powder Metallurgy ◽  
Friction Coefficient ◽  
Tribological Properties ◽  
Utilization Rate ◽  
Powder Metallurgy Technique ◽  
Aluminum Composite ◽  
Powder Metallurgy Process ◽  
Metallurgy Process ◽  
Composite Samples

In order to make full use of the wear resistance and antifriction of the mixed reinforced particles, improve the performance and utilization rate of the composite material, and reduce its wear amount, in this study, graphite and aluminum composite materials with different graphite concentration were prepared by powder metallurgy process. On this basis, the influence of different graphite concentration on the friction coefficient and wear amount of composite samples and different load on the wear amount of composite materials were discussed and analyzed. The results show that with the increase of graphite content, the friction coefficient and wear amount of the composite will decrease correspondingly. When the load is less than 30 N, the wear curve of the sample changes steadily. When the load is more than 30 N, the wear will increase sharply. Therefore, the analysis of the tribological properties of the graphite and aluminum composites based on the powder metallurgy process plays an important role in improving the utilization rate of the composite and reducing its wear.

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.

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.

Effect of CNTs on Properties of Cu-Based Composites and Mechanism

2012 ◽  
Vol 557-559 ◽  
pp. 262-266
Author(s):  
Gui Min Liu ◽  
Bin Li ◽  
Jian Hua Du ◽  
Xiao Hui Zheng
Keyword(s):  
Powder Metallurgy ◽  
Friction Coefficient ◽  
Tribological Properties ◽  
Wear Property ◽  
Friction Tester ◽  
Density Values ◽  
Disk Friction ◽  
Carbon Nano Tubes ◽  
Microstructure Density ◽  
Hardness Values

The Carbon nano-tubes (CNTs) reinforced Cu-based (CNTs/Cu) composites were obtained by powder metallurgy processes. The effects of CNTs content on the microstructure, density and hardness of the Cu-based composites were investigated. The tribological properties of the composites were studied by using a ball/disk friction tester. The results indicate that the density values of the composites gradually decrease with the increment of CNTs content, while for the hardness values, firstly increase and then decrease; and the maximal hardness values was obtained when the composite contains 0.75% CNTs. The CNTs content exerts a great effect on the friction coefficient of the composite. It has been found that the anti-wear property of the CNTs/Cu composites is excellent, at the same time, the hardness and density values are also in the reasonable ranges when the CNTs content is relatively low. The concerning mechanism has been analyzed in the present paper.

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.

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.

Improvement of Tribological Properties by Titanium Nitride Deposition in Titanium Alloys Produced by Powder Metallurgy

2012 ◽  
Vol 727-728 ◽  
pp. 480-485 ◽  
Author(s):  
Eduardo T. Galvani ◽  
V.A.R. Henriques ◽  
T.G. Lemos
Keyword(s):  
Electron Beam ◽  
Powder Metallurgy ◽  
Titanium Nitride ◽  
Titanium Alloys ◽  
Tribological Properties ◽  
Physical Vapor Deposition ◽  
High Vacuum ◽  
Hard Material ◽  
Wear Properties ◽  
Tin Films

Titanium nitride (TiN) is a hard material, often used as coating to improve the wear properties of titanium alloys in machining, implant and aerospace applications. Electron Beam Physical Vapor Deposition (EB-PVD) is a technique which a target anode is bombarded with an electron beam given off by a charged tungsten filament under high vacuum, producing a thin film in a substrate. In this work, results of TiN films depositions on Ti-13Nb-13Zr substrates by EB-PVD are studied. Titanium targets were obtained by a purified ingot and the substrates produced by powder metallurgy. Sintered samples of Ti-13Nb-13Zr and TiN layers were characterized by X-ray diffraction, scanning electron microscopy, Vickers microhardness and wear tests. The TiN films presented high hardness values, continuity and large thickness. The coatings improved the tribological properties of the substrate due to high adhesion and low wear rate.

scholarly journals Deposition and Tribological Properties of Sulfur-Doped DLC Films Deposited by PBII Method

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Nutthanun Moolsradoo ◽  
Shuichi Watanabe
Keyword(s):  
Elastic Modulus ◽  
Friction Coefficient ◽  
Sulfur Content ◽  
Bias Voltage ◽  
Tribological Properties ◽  
Relative Concentration ◽  
High Vacuum ◽  
Ambient Air ◽  
Flow Rate Ratio ◽  
Negative Pulse

Sulfur-doped diamond-like carbon films (S-DLC) fabricated fromC2H2andSF6mixtures were used to study the effects of sulfur content and negative pulse bias voltage on the deposition and tribological properties of films prepared by plasma-based ion implantation (PBII). The structure and relative concentration of the films were analyzed by Raman spectroscopy and Auger electron spectroscopy. Hardness and elastic modulus of films were measured by nanoindentation hardness testing. Tribological characteristics of films were performed using a ball-on-disk friction tester. The results indicate that with the increasing sulfur content, the hardness and elastic modulus decrease. Additionally, by changing the negative pulse bias voltage from 0 kV to−5 kV, the hardness and elastic modulus increase, while the friction coefficient and specific wear rate tends to decrease. Moreover, at a negative pulse bias voltage of−5 kV and flow-rate ratio of 1 : 2, there is considerable improvement in friction coefficient of 0.05 under ambient air is due to the formation of a transfer films on the interface. The decrease in the friction coefficient of films doped with 4.9 at.% sulfur is greater under high vacuum (0.03) than under ambient air (>0.1).

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.

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