scholarly journals Experimental Evaluation of Oxide Nanoparticles as Friction and Wear Improvement Additives in Motor Oil

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Nicholaos G. Demas ◽  
Robert A. Erck ◽  
Cinta Lorenzo-Martin ◽  
Oyelayo O. Ajayi ◽  
George R. Fenske
Keyword(s):  
Laboratory Test ◽  
Coefficient Of Friction ◽  
Friction And Wear ◽  
Oxide Nanoparticles ◽  
Test Machine ◽  
Motor Oil ◽  
Test Configuration ◽  
Test Conditions ◽  
Contact Configuration ◽  
The Coefficient Of Friction

The effect of two nanoparticle oxides on friction and wear was studied under laboratory test conditions using a reciprocating test machine and two test configurations. The addition of these nanoparticles in base stock oil under certain conditions reduced the coefficient of friction and improved wear, but that depended on the test configuration. Examination of the rubbed surfaces showed the pronounced formation of a tribofilm in some cases, while polishing on the surface was also observed in other cases. Contact configuration is important when oxide nanoparticles are being evaluated and the conclusions about their efficacy can be vastly different.

Sliding friction and wear behavior of Al–Ni–Co–Si quasicrystalline coatings deposited by the high-velocity oxy-fuel spraying technique

2002 ◽  
Vol 17 (2) ◽  
pp. 492-501 ◽  
Author(s):  
Eric Fleury ◽  
Yu-Chan Kim ◽  
Jae-Soo Kim ◽  
Hyo-Sok Ahn ◽  
Sang-Mok Lee ◽  
...  
Keyword(s):  
Coefficient Of Friction ◽  
High Velocity ◽  
Wear Debris ◽  
Friction And Wear ◽  
Sliding Friction ◽  
Wear Behavior ◽  
Stick Slip ◽  
Friction And Wear Behavior ◽  
Test Conditions ◽  
The Coefficient Of Friction

The sliding friction and wear performance of Al–Ni–Co–Si quasicrystalline coatings deposited by the high-velocity oxy-fuel technique were investigated under dry sliding conditions. This study indicated that changes in the imposed sliding test conditions modified the friction and wear behavior of quasicrystalline coatings. Qualitative analysis of the contact interface and wear debris were performed with the aim of understanding the role of the third body on the friction and wear processes. The dependence of the coefficient of friction on the sliding velocity and counterpart material was explained by the stick-slip behavior. It was also shown that test conditions favorable for the formation of thick intermediate layers and the densification of the coating subsurface led to low wear rates. Large cylindrical particles, formed by agglomeration of small wear debris, were suggested as a beneficial factor for the reduction of 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.

Comparative Study of Unprotected vs. Protected Surfaces Using an Innovative Process for Applying Solid Lubricants to Reduce Friction and Wear

Tribology ◽  
2005 ◽  
Author(s):  
Jane E. Buehler ◽  
K. Dean Bowles
Keyword(s):  
Coefficient Of Friction ◽  
Friction And Wear ◽  
Solid Lubricants ◽  
Wear Coefficient ◽  
Sliding Speed ◽  
Speed Test ◽  
Speed Condition ◽  
Test Conditions ◽  
Pin On Disc ◽  
Lower Load

Two tribocouples were compared neat vs. treated with Induratec™. The tribocouples, tested under dry sliding conditions via a pin-on-disc tribometer, were 52100 steel ball on 52100 steel disc and 8620 steel pin on C67300 bronze disc. Comparisons of coefficient of friction and wear coefficient, K (mm3/N m) are presented. For the 52100 tribocouple two test conditions were completed, a 9.8 N load at 0.75 m/s and a 29.4 N load at 2.0 m/s. The coefficient of friction, for the treated samples compared to the untreated samples, was reduced by 74% for the lower load and speed condition and by 79% for the higher load and speed condition. For the lower load and speed test condition, the wear coefficient was reduced by a factor of 55 and for the higher load and speed condition the wear coefficient was reduced by a factor of 887. For the 8620 steel pin on C67300 bronze disc, two test conditions were completed, a 9.8 N load at 2.5 m/s sliding speed and a 19.6 N load also at 2.5 m/s sliding speed. The treated surface had a 42% lower coefficient of friction at the 9.8 N load and a 57% lower coefficient of friction at the 19.6 N load. The treated tribocouple wear coefficient was reduced by a factor of 600 for the 9.8 N load and by a factor of 1733 for the 19.6 N load.

scholarly journals Tribological capabilities of chiral nematic liquid crystal additives in mineral motor oil

2020 ◽  
Vol 12 (7) ◽  
pp. 168781402094547
Author(s):  
Vadim Mokshin
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Coefficient Of Friction ◽  
Friction Pair ◽  
Contact Temperature ◽  
Test Machine ◽  
Regression Equations ◽  
Motor Oil ◽  
Oil Additives ◽  
Chiral Nematic

This article presents the results of experimental investigation of tribological properties of commercial mineral motor oil with chiral nematic (also known as twisted nematic or cholesteric) liquid crystal additives. Cholesteryl stearate and valerate (fatty acid cholesterol esters) liquid crystals were used as oil additives in investigation. Tribological experiments were performed using a block-on-disc-type tribo-test machine at constant experiment time and sliding velocity conditions. The load (contact pressure), concentration of liquid crystalline additive in oil and Rz roughness of steel–steel friction surfaces were taken as variable parameters. The mean coefficient of friction of steel–steel friction pair lubricated by oil with and without liquid crystal additives and near-contact temperature were taken as dependent variables. Regression equations were then derived for each lubricant and tribological efficiency of liquid crystals as oil additives was evaluated. It was established that coefficient of friction of steel–steel friction pair and near-contact temperature are reduced to about a half in the presence of liquid crystal additives. Results of tribological experiments show that tribological efficiency of liquid crystals as oil additives increases with increase in their molecular mass.

scholarly journals The Effect of Surface Texture on Lubricated Fretting

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4886
Author(s):  
Agnieszka Lenart ◽  
Pawel Pawlus ◽  
Andrzej Dzierwa ◽  
Slawomir Wos ◽  
Rafal Reizer
Keyword(s):  
Coefficient Of Friction ◽  
Surface Texture ◽  
Friction And Wear ◽  
Normal Load ◽  
Disc Surface ◽  
The Coefficient Of Friction ◽  
42Crmo4 Steel ◽  
Ball Diameter ◽  
Steel Balls ◽  
Effect Of Surface

Experiments were conducted using an Optimol SRV5 tester in lubricated friction conditions. Steel balls from 100Cr6 material of 60 HRC hardness were placed in contact with 42CrMo4 steel discs of 47 HRC hardness and diversified surface textures. Tests were carried out at a 25–40% relative humidity. The ball diameter was 10 mm, the amplitude of oscillations was set to 0.1 mm, and the frequency was set to 80 Hz. Tests were performed at smaller (45 N) and higher (100 N) normal loads and at smaller (30 °C) and higher (90 °C) temperatures. During each test, the normal load and temperature were kept constant. We found that the disc surface texture had significant effects on the friction and wear under lubricated conditions. When a lower normal load was applied, the coefficient of friction and wear volumes were smaller for bigger disc surface heights. However, for a larger normal load a higher roughness corresponded to a larger coefficient of friction.

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