Tribological performances of graphite–MoS2 coating at various high temperatures

2019 ◽  
Vol 233 (12) ◽  
pp. 1888-1902 ◽  
Author(s):  
Huali Han ◽  
Zhiyuan Qian ◽  
Fanming Meng ◽  
Zhongtao Cui
Keyword(s):  
High Temperatures ◽  
Coefficient Of Friction ◽  
Rotational Speed ◽  
Friction And Wear ◽  
Applied Load ◽  
Wear Scar ◽  
Graphite Content ◽  
Critical Rotational Speed ◽  
The Coefficient Of Friction ◽  
Scar Width

The tribological performances of the graphite–MoS2 coating deposited on the disc specimen, whose material is GCr15 steel, are experimentally investigated under high temperatures. Effects of graphite content, applied load, rotational speed and test temperature on the coefficient of friction and wear scar width of the coating are evaluated. The graphite–MoS2 coating with 20 wt% graphite addition exhibits the relatively small coefficient of friction and wear scar width at 200 ℃. At or beyond 400 ℃, the coating's lubricating effect is severely deteriorated with the testing time. At 200 ℃, there exists a critical applied load of 10 N and a critical rotational speed of 1250 rpm beyond which the MoS2 coating with 20 wt% graphite content is worn through and brings out a large coefficient of friction. The test results indicate that adding 20 wt% to 33 wt% graphite to MoS2 coating leads to an obvious reduction of the coefficient of friction and wear scar width for the coating at 200 ℃.

Experimental Study on Tribological Properties of Graphite-MoS2 Coating on GCr15

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
F. M. Meng ◽  
Z. T. Cui ◽  
Z. T. Cheng ◽  
H. L. Han
Keyword(s):  
Experimental Study ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Rotational Speed ◽  
Applied Load ◽  
Bearing Steel ◽  
Experimental Results ◽  
Gcr15 Bearing Steel ◽  
Mos2 Coating ◽  
Scar Width

The graphite-MoS2 coated on GCr15 bearing steel is prepared through air spraying and its tribological performances are investigated experimentally. Then its coefficient of friction (COF) and wear scar width (WSW) are investigated through the MFT-5000 multifunction tribometer and other test equipments. The experimental results show that the addition of the graphite can effectively decrease the COF and narrow the WSW of the MoS2. There exists a critical applied load for wearing out the surface with the graphite-MoS2 coating. Moreover, there exists an optimal rotational speed of 500 rpm to decrease the COF and WSW of the GCr15 steel.

scholarly journals Tribological Aspects, Optimization and Analysis of Cu-B-CrC Composites Fabricated by Powder Metallurgy

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4217
Author(s):  
Üsame Ali Usca ◽  
Mahir Uzun ◽  
Mustafa Kuntoğlu ◽  
Serhat Şap ◽  
Khaled Giasin ◽  
...  
Keyword(s):  
Weight Loss ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Applied Load ◽  
Practical Significance ◽  
Tribological Characteristics ◽  
M 10 ◽  
Wide Range ◽  
The Coefficient Of Friction ◽  
Four Levels

Tribological properties of engineering components are a key issue due to their effect on the operational performance factors such as wear, surface characteristics, service life and in situ behavior. Thus, for better component quality, process parameters have major importance, especially for metal matrix composites (MMCs), which are a special class of materials used in a wide range of engineering applications including but not limited to structural, automotive and aeronautics. This paper deals with the tribological behavior of Cu-B-CrC composites (Cu-main matrix, B-CrC-reinforcement by 0, 2.5, 5 and 7.5 wt.%). The tribological characteristics investigated in this study are the coefficient of friction, wear rate and weight loss. For this purpose, four levels of sliding distance (1000, 1500, 2000 and 2500 m) and four levels of applied load (10, 15, 20 and 25 N) were used. In addition, two levels of sliding velocity (1 and 1.5 m/s), two levels of sintering time (1 and 2 h) and two sintering temperatures (1000 and 1050 °C) were used. Taguchi’s L16 orthogonal array was used to statistically analyze the aforementioned input parameters and to determine their best levels which give the desired values for the analyzed tribological characteristics. The results were analyzed by statistical analysis, optimization and 3D surface plots. Accordingly, it was determined that the most effective factor for wear rate, weight loss and friction coefficients is the contribution rate. According to signal-to-noise ratios, optimum solutions can be sorted as: the highest levels of parameters except for applied load and reinforcement ratio (2500 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 0 wt.%) for wear rate, certain levels of all parameters (1000 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 2.5 wt.%) for weight loss and 1000 m, 15 N, 1 m/s, 1 h, 1000 °C and 0 wt.% for the coefficient of friction. The comprehensive analysis of findings has practical significance and provides valuable information for a composite material from the production phase to the actual working conditions.

The effects of applied load on the coefficient of friction in Cu-MMC brake pad/Al-SiCp MMC brake disc system

Wear ◽  
2010 ◽  
Vol 270 (1-2) ◽  
pp. 73-82 ◽  
Author(s):  
D. Gultekin ◽  
M. Uysal ◽  
S. Aslan ◽  
M. Alaf ◽  
M.O. Guler ◽  
...  
Keyword(s):  
Coefficient Of Friction ◽  
Applied Load ◽  
Brake Disc ◽  
Brake Pad ◽  
The Coefficient Of Friction

Some Tribological Properties of an Ionic Liquid

2005 ◽  
Author(s):  
Takashi Nogi
Keyword(s):  
Ionic Liquid ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Friction And Wear ◽  
Wear Performance ◽  
Lubrication Regime ◽  
Pin On Disc ◽  
The Coefficient Of Friction

Some tribological properties of an ionic liquid were investigated by using a pin-on-disc friction and wear tester. Due to running-in, the coefficient of friction of the ionic liquid decreased with time to a very low value of 0.02 which suggests that the lubrication regime was hydrodynamic at the end of the tests. Anti-wear performance of the ionic liquid was substantially comparable to a paraffin-based oil.

Study on the Friction and Wear Characteristics of Tungsten Carbide and Zirconium With Phosphor-Containing Liquid

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Myeong-Woo Ha ◽  
Kwang-Hee Lee ◽  
Chul-Hee Lee ◽  
Jong-Myung Choi ◽  
Jun-Wook An
Keyword(s):  
Tungsten Carbide ◽  
Coefficient Of Friction ◽  
Contact Surface ◽  
Friction And Wear ◽  
Yttrium Aluminum Garnet ◽  
Experimental Results ◽  
Wear Characteristics ◽  
Hard Materials ◽  
The Coefficient Of Friction ◽  
Friction And Wear Characteristics

The dispenser ejects the ceramic filler and phosphor-containing liquid for making various products. When the particle-containing liquid is ejected under high-velocity conditions, however, the ejection reliability decreases because of the wear of the contact surface between the rod and nozzle even though these components are made of hard materials. It is therefore necessary to characterize the friction and wear properties of the hard materials, tungsten carbide (WC) and zirconium (Zr), with the high-viscosity liquid-containing nitride or yttrium aluminum garnet (YAG) particles under reciprocating conditions. Particle contents of 15 wt.% and 30 wt.% are added to the liquid. A reciprocating test was implemented to this end, and WC and Zr specimens were used. The liquid used in the experiment contains nitride and YAG. The experimental results show that the particles inside the liquid are worn out, leading to particle lubrication and the decrease in the coefficient of friction. Also, it is confirmed that the more the particles are, the less the coefficient of friction is due to particle lubrication. For each experimental condition, the coefficient of friction is measured and compared. Moreover, the contact surface of the specimen is analyzed using an electron microscope, and a profilometer is used to measure the surface roughness of the specimen before and after the test. The reciprocation friction and wear characteristics of WC and Zr with phosphor-containing liquid are evaluated by analyzing the experimental results.

Friction and wear studies of silicon in sliding contact with thin-film magnetic rigid disks

1993 ◽  
Vol 8 (7) ◽  
pp. 1611-1628 ◽  
Author(s):  
Bharat Bhushan ◽  
Sreekanth Venkatesan
Keyword(s):  
Thin Film ◽  
Single Crystal ◽  
Coefficient Of Friction ◽  
Amorphous Carbon ◽  
Friction And Wear ◽  
Single Crystal Silicon ◽  
Crystal Silicon ◽  
Carbon Transfer ◽  
Zn Ferrite ◽  
The Coefficient Of Friction

Silicon is an attractive material for the construction of read/write head sliders in magnetic recording applications from the viewpoints of ease of miniaturization and low fabrication cost. In the present investigation we have studied the friction and wear behavior of single-crystal, polycrystalline, ion-implanted, thermally oxidized (wet and dry), and plasma-enhanced chemical vapor deposition (PECVD) oxide-coated silicon pins while sliding against lubricated and unlubricated thin-film disks. For comparison, tests have also been conducted with Al2O3–TiC and Mn–Zn ferrite pins which are currently used as slider materials. With single-crystal silicon the rise in the coefficient of friction with sliding cycles is faster compared to Al2O3–TiC and Mn–Zn ferrite pins. In each case, the rise in friction is associated with the burnishing of the disk surface and transfer of amorphous carbon and lubricant (in the case of lubricated disks) from the disk to the pin. Thermally oxidized (under dry oxygen conditions) single-crystal silicon and PECVD oxide-coated single-crystal silicon exhibit excellent tribological characteristics while sliding against lubricated disks, and we believe this is attributable to the chemical passivity of the oxide coating. In dry nitrogen, the coefficient of friction for single-crystal silicon sliding against lubricated disks behaves differently than in air, decreasing from an initial value of 0.2 to less than 0.05 within 5000 cycles of sliding. We believe that silicon/thin-film disk interface friction and wear is governed by the uniformity and tenacity of the amorphous carbon transfer film and oxygen-enhanced fracture of silicon.

scholarly journals A Factorial Design to Numerically Study the Effects of Brake Pad Properties on Friction and Wear Emissions

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Jens Wahlström
Keyword(s):  
Factorial Design ◽  
Coefficient Of Friction ◽  
Friction And Wear ◽  
Friction Material ◽  
Particulate Emissions ◽  
Third Body ◽  
Wear Process ◽  
Disc Brakes ◽  
The Coefficient Of Friction ◽  
Contact Situation

Airborne particulate emissions originating from the wear of pads and rotors of disc brakes contribute up to 50% of the total road emissions in Europe. The wear process that takes place on a mesoscopic length scale in the contact interfaces between the pads and rotors can be explained by the creation and destruction of contact plateaus. Due to this complex contact situation, it is hard to predict how changes in the wear and material parameters of the pad friction material will affect the friction and wear emissions. This paper reports on an investigation of the effect of different parameters of the pad friction material on the coefficient of friction and wear emissions. A full factorial design is developed using a simplified version of a previously developed cellular automaton approach to investigate the effect of four factors on the coefficient of friction and wear emission. The simulated result indicates that a stable third body, a high specific wear, and a relatively high amount of metal fibres yield a high and stable mean coefficient of friction, while a stable third body, a low specific wear, a stable resin, and a relatively high amount of metal fibres give low wear emissions.

scholarly journals Sintered Hydroxyapatite Ceramic for Wear Studies

1978 ◽  
Vol 57 (7-8) ◽  
pp. 777-783 ◽  
Author(s):  
Hillar M. Rootare ◽  
John M. Powers ◽  
Robert G. Craig
Keyword(s):  
Coefficient Of Friction ◽  
Tricalcium Phosphate ◽  
Friction And Wear ◽  
Tangential Force ◽  
Hydroxyapatite Ceramic ◽  
Track Width ◽  
Failure Data ◽  
Surface Failure ◽  
Human Enamel ◽  
The Coefficient Of Friction

A sintered hydroxyapatite (HAP) ceramic for use in wear studies was prepared from a commerical tricalcium phosphate. The sintered HAP had physical properties close to those of human enamel. The coefficient of friction and wear of the sintered HAP ceramic as characterized by tangential force, track width, and surface failure data, approximated those of human enamel.

A novel nonlinear nano-scale wear law for metallic brake pads

2018 ◽  
Vol 20 (17) ◽  
pp. 12027-12036 ◽  
Author(s):  
Sandeep P. Patil ◽  
Sri Harsha Chilakamarri ◽  
Bernd Markert
Keyword(s):  
Molecular Dynamics ◽  
Temperature Distribution ◽  
Coefficient Of Friction ◽  
Friction And Wear ◽  
Brake Pads ◽  
Braking System ◽  
System P ◽  
The Coefficient Of Friction ◽  
Dynamics Simulations ◽  
Wear Law

In the present work, molecular dynamics simulations were carried out to investigate the temperature distribution as well as the fundamental friction characteristics such as the coefficient of friction and wear in a disc-pad braking system.

Experimental investigation on the tribological properties of modified carbon nanotubes as the additive in castor oil

2018 ◽  
Vol 70 (3) ◽  
pp. 499-505
Author(s):  
Shanhua Qian ◽  
Hongyue Wang ◽  
Chuanhui Huang ◽  
Yongwu Zhao
Keyword(s):  
Carbon Nanotubes ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Castor Oil ◽  
Friction And Wear ◽  
Engineering Application ◽  
Wear Scar ◽  
Wear Scar Diameter ◽  
Content Type ◽  
Modified Carbon Nanotubes

Purpose This paper aims to modify carbon nanotubes with oleic acid, and to study the tribological properties of castor oil with modified carbon nanotubes additives. The proper additives are sought for the future engineering application of castor oil. Design/methodology/approach Tribological properties of the castor oils mixed with the modified carbon nanotubes of four mass percentages were investigated using a four-ball testing rig. Coefficient of friction and wear scar diameter were obtained in each test, and the mechanism of modified carbon nanotubes and castor oil was discussed. Findings The results indicated that modified carbon nanotubes had better dispersion in castor oil. Coefficient of friction first increased, then decreased and finally grew stable with the time, and wear scar diameter of steel surface functioned as a first reduced then increased change with the additive mass percentage of modified carbon nanotubes. The minimum of average coefficient of friction and wear scar diameter occurred at 0.02 Wt.% modified carbon nanotubes. Originality/value A small amount of modified carbon nanotubes could improve properties of the castor oil, and the mixed castor oil with 0.02 Wt.% modified carbon nanotubes would be most possibly used in engineering applications.

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