scholarly journals Wear depth calculation and influence factor analysis for groove ball bearing

2018 ◽  
Vol 211 ◽  
pp. 08002
Author(s):  
Fengxia Lu ◽  
Rupeng Zhu ◽  
Qiuju Fu
Keyword(s):  
Friction Coefficient ◽  
Influence Factor ◽  
Contact Region ◽  
Wear Depth ◽  
Roll Body ◽  
Cycle Times ◽  
Body Diameter ◽  
Pure Rolling ◽  
Curvature Coefficient ◽  
Contact Ellipse

Based on Hertz contact theory and load distribution, the formulas for contact stress cycle times, slip distance and wear depth measurements are derived, and the influences of load, curvature coefficient, roll body diameter and friction coefficient on the contact region wear depth and distributions are thoroughly analyzed. The results show that the wear depth is zero at the pure rolling point and the long half-axle terminals of contact ellipse, and reaches maximum value near by the long half-axle terminals of the contact ellipse, and further shows that the wear depth increases with increase of the load and friction coefficient, however decreases with increase of the curvature coefficient and roll body diameter.

scholarly journals Estimation of Wear Resistance for Multilayer Coatings Obtained by Nitrogenchroming

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1153
Author(s):  
Ivan Pavlenko ◽  
Jozef Zajac ◽  
Nadiia Kharchenko ◽  
Ján Duplák ◽  
Vitalii Ivanov ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Spectral Analysis ◽  
Friction Coefficient ◽  
Cutting Tools ◽  
Wear Intensity ◽  
Maximum Amount ◽  
Multilayer Coatings ◽  
Wear Depth ◽  
X Ray ◽  
Machine Parts

This article deals with improving the wear resistance of multilayer coatings as a fundamental problem in metal surface treatment, strengthening elements of cutting tools, and ensuring the reliability of machine parts. It aims to evaluate the wear depth for multilayer coatings by the mass loss distribution in layers. The article’s primary purpose is to develop a mathematical method for assessing the value of wear for multilayer steel-based coatings. The study material is a multilayer coating applied to steel DIN C80W1. The research was performed using up-to-date laboratory equipment. Nitrogenchroming has been realized under overpressure in two successive stages: nitriding for 36 h at temperature 540 °C and chromizing during 4 h at temperature 1050 °C. The complex analysis included several options: X-ray phase analysis, local micro-X-ray spectral analysis, durometric analysis, and determination of wear resistance. These analyses showed that after nitrogenchroming, the three-layer protective coating from Cr23C6, Cr7C3, and Cr2N was formed on the steel surface. Spectral analysis indicated that the maximum amount of chromium 92.2% is in the first layer from Cr23C6. The maximum amount of carbon 8.9% characterizes the layer from Cr7C3. Nitrogen is concentrated mainly in the Cr2N layer, and its maximum amount is 9.4%. Additionally, it was determined that the minimum wear is typical for steel DIN C80W1 after nitrogenchroming. The weight loss of steel samples by 25 mg was obtained. This value differs by 3.6% from the results evaluated analytically using the developed mathematical model of wear of multilayer coatings after complex metallization of steel DIN C80W1. As a result, the impact of the loading mode on the wear intensity of steel was established. As the loading time increases, the friction coefficient of the coated samples decreases. Among the studied samples, plates from steel DIN C80W1 have the lowest friction coefficient after nitrogenchroming. Additionally, a linear dependence of the mass losses on the wearing time was obtained for carbide and nitride coatings. Finally, an increase in loading time leads to an increase in the wear intensity of steels after nitrogenchroming. The achieved scientific results are applicable in developing methods of chemical-thermal treatment, improving the wear resistance of multilayer coatings, and strengthening highly loaded machine parts and cutting tools.

scholarly journals Comparison between multi-walled carbon nanotubes and titanium dioxide nanoparticles as additives on performance of turbine meter oil nano lubricant

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hadi Pourpasha ◽  
Saeed Zeinali Heris ◽  
Yaghob Mohammadfam
Keyword(s):  
Carbon Nanotubes ◽  
Titanium Dioxide ◽  
Friction Coefficient ◽  
Pressure Drop ◽  
Mass Fraction ◽  
Viscosity Index ◽  
Wear Depth ◽  
Nano Lubricant ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

AbstractThis research aims of compare the impact of the mass fraction of multi-walled carbon nanotubes (MWCNTs) and titanium dioxide (TiO2) nano additive on the tribological and thermophysical attributes of turbine meter oil. These attributes include the average friction coefficient, pressure drop, wear, flash point, pour point, relative viscosity, kinematics viscosity, and viscosity index. The pressure drops and the average friction coefficient inside the copper tube were simulated and compared with experimental results. In this study, for the synthesis of nano lubricants from turbine meter oil as a pure fluid and from MWCNTs and TiO2 as nano additives in the mass fraction of 0.05, 0.1, 0.2, 0.3, and 0.4 wt.% and from oleic acid and Triton x100 as surfactants were utilized. The results illustrated that the wear depth of copper pins in the presence of nano lubricant with 0.4 wt.% of MWCNTs and 0.1 wt.% TiO2 was improved by 88.26% and 71.43%, respectively. Increasing 0.3 wt.% of TiO2 and MWCNTs into the oil caused to improvement in viscosity index. The simulation data and experimental data for the pressure drop were closer together and indicated a minor error that the maximum error is less than 10%.

scholarly journals On rolling friction

2019 ◽  
Vol 485 (3) ◽  
pp. 295-299
Author(s):  
A. P. Ivanov
Keyword(s):  
Friction Coefficient ◽  
Angular Velocity ◽  
Viscous Friction ◽  
Rolling Friction ◽  
The Body ◽  
Normal Velocity ◽  
Contact Conditions ◽  
Combined Motion ◽  
Pure Rolling ◽  
Over Time

The dependence of rolling friction on velocity for various contact conditions is discussed. The principal difference between rolling and other types of relative motion (sliding and spinning) is that the points of the body in contact with the support change over time. Due to deformations, there is a small contact area and, entering into contact, the body points have a normal velocity proportional to the diameter of this area. For describing the dependence of the friction coefficient on the angular velocity in the case of “pure” rolling, a linear dependence is proposed that admits a logical explanation and experimental verification. Under the combined motion, the rolling friction retains its properties, the sliding and spinning friction acquiring the properties of viscous friction.

A Mixed-TEHL Analysis of Cam-Roller Contacts Considering Roller Slip: On the Influence of Roller-Pin Contact Friction

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Shivam S. Alakhramsing ◽  
Matthijn B. de Rooij ◽  
Aydar Akchurin ◽  
Dirk J. Schipper ◽  
Mark van Drogen
Keyword(s):  
Friction Coefficient ◽  
Thermal Effects ◽  
Mixed Lubrication ◽  
Contact Friction ◽  
Sudden Increase ◽  
Low Friction ◽  
Pure Rolling ◽  
Lubrication Performance ◽  
Cam Follower ◽  
Film Lubrication

In this work, a mixed lubrication model, applicable to cam-roller contacts, is presented. The model takes into account non-Newtonian, thermal effects, and variable roller angular velocity. Mixed lubrication is analyzed using the load sharing concept, using measured surface roughness. Using the model, a quasi-static analysis for a heavily loaded cam-roller follower contact is carried out. The results show that when the lubrication conditions in the roller-pin contact are satisfactory, i.e., low friction levels, then the nearly “pure rolling” condition at the cam-roller contact is maintained and lubrication performance is also satisfactory. Moreover, non-Newtonian and thermal effects are then negligible. Furthermore, the influence of roller-pin friction coefficient on the overall tribological behavior of the cam-roller contact is investigated. In this part, a parametric study is carried out in which the friction coefficient in the roller-pin contact is varied from values corresponding to full film lubrication to values corresponding to boundary lubrication. Main findings are that at increasing friction levels in the roller-pin contact, there is a sudden increase in the slide-to-roll ratio (SRR) in the cam-roller contact. The value of the roller-pin friction coefficient at which this sudden increase in SRR is noticed depends on the contact force, the non-Newtonian characteristics, and viscosity–pressure dependence. For roller-pin friction coefficient values higher than this critical value, inclusion of non-Newtonian and thermal effects becomes highly important. Furthermore, after this critical level of roller-pin friction, the lubrication regime rapidly shifts from full film to mixed lubrication. Based on the findings in this work, the importance of ensuring adequate lubrication in the roller-pin contact is highlighted as this appears to be the critical contact in the cam-follower unit.

Tribological behavior and film-forming mechanism of a polytetrafluoroethylene/polyester fabric composite

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Juan Wang ◽  
Xiongrong Huang ◽  
Wei Wang ◽  
Haosheng Han ◽  
Hongyu Duan ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
High Speed ◽  
Tribological Behavior ◽  
Elemental Content ◽  
Wear Depth ◽  
Content Type ◽  
Pet Fabric ◽  
Forming Mechanism ◽  
Fabric Composite ◽  
Film Forming

Purpose The purpose of this study is to determine the tribological behavior and wear mechanism of a polytetrafluoroethylene (PTFE)/polyester (PET) fabric composite for application as a self-lubricating liner suitable for high-speed and low-load friction conditions. Design/methodology/approach The effects of different loads and sliding speeds on the friction coefficients and wear characteristics of the composite were studied using reciprocating friction tests. Scanning electron microscopy, extended depth-of-field microscopy, and energy-dispersive X-ray spectrometry was used to analyze the worn surface morphology, wear depth and elemental content of the lubrication films, respectively. Findings The friction coefficient curves of the composites presented a long-term steady wear stage under different sliding conditions. With increasing sliding speed, the friction coefficient and wear depth of the composite slowly increased. The film-forming mechanism of the composite revealed that the PTFE/PET ply yarn on the composite surface formed complete PTFE lubrication films at the initial sliding stage. Originality/value The PTFE/PET fabric composite maintained good friction stability and high-speed adaptability, which demonstrates that the composite has broad application prospects as a highly reliable self-lubricating bearing liner with a long lifespan.

Friction coefficient study of nanocomposite Al2O3–NbC obtained by spark plasma sintering-SPS

2020 ◽  
Vol 72 (9) ◽  
pp. 1087-1094
Author(s):  
Susan Meireles C. Dantas ◽  
Marcio G. Di Vernieri Cuppari ◽  
Vania Trombini Hernandes
Keyword(s):  
Friction Coefficient ◽  
Peer Review ◽  
Spark Plasma Sintering ◽  
Contact Region ◽  
Content Type ◽  
3D Profilometry ◽  
Plasma Sintering ◽  
Dry Conditions ◽  
Spark Plasma ◽  
Surface Changes

Purpose This study aims to investigate the friction coefficient of Al2O3–NbC nanocomposite obtained by spark plasma sintering sliding against a steel ball. Design/methodology/approach Tribological tests were carried out using a reciprocating nanotribometer in a ball on flat configuration with normal loads in the range from 10 to 100 mN under dry conditions. Surface changes were analyzed by confocal microscopy and 3D profilometry. Findings The values of the friction coefficient varied from 0.15 to 0.6 and are independent of the applied load. Originality/value The tribological behavior is attributed to fracture in the contact region and the effect of wear debris. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2019-0356/

Numerical Prediction of Surface Wear and Roughness Parameters During Running-In for Line Contacts Under Mixed Lubrication

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Yazhao Zhang ◽  
Alexander Kovalev ◽  
Noriyuki Hayashi ◽  
Kensuke Nishiura ◽  
Yonggang Meng
Keyword(s):  
Friction Coefficient ◽  
Contact Region ◽  
Mixed Lubrication ◽  
Asperity Contact ◽  
Wear Particles ◽  
Wear Model ◽  
Wear Process ◽  
Line Contacts ◽  
Lubrication Condition ◽  
Initial Line

A stochastic model for predicting the evolutions of wear profile and surface height probability density function (PDF) of initial line contacts during running-in under mixed lubrication condition is presented. A numerical approach was developed on the basis of stochastic solution of mixed lubrication, which combined the Patir and Cheng's average flow model for calculation of the hydrodynamic pressure and the Kogut and Etsion's (KE) rough surface contact model for calculation of the asperity contact pressure. The total friction force was assumed to be the sum of the boundary friction at the contact asperities and the integration of viscous shear stress in the hydrodynamic region. The wear depth on the contact region was estimated according to the modified Archard's wear model using the asperity contact pressure. Sugimura's wear model was modified and used to link the wear particle size distribution and the variation of surface height PDF during wear. In the wear process, the variations of profile and surface height PDF of initial line contacts were calculated step by step in time, and the pressure distribution, friction coefficient, and wear rate were updated consequently. The effect of size distribution of wear particles on the wear process was numerically investigated, and the simulation results showed that the lubrication condition in which small wear particles are generated from the asperity contact region is beneficial to reduce friction coefficient and wear rate, and leads to a better steady mixed lubrication condition.

A Study of the Effect of m and n Coefficients of the Hertzian Contact Theory on Railroad Vehicle Dynamics

2007 ◽  
Author(s):  
J. P. Pascal ◽  
Khaled E. Zaazaa
Keyword(s):  
Contact Area ◽  
Contact Region ◽  
Local Deformation ◽  
Hertzian Contact ◽  
Vehicle Dynamic ◽  
Railroad Vehicle Dynamics ◽  
Original Table ◽  
Data Points ◽  
Railroad Vehicle ◽  
Contact Ellipse

For the wheel/rail contact problem, the Hertz theory for two elastic bodies in contact is commonly used to determine the shape and dimensions of the contact area and the local deformation of the wheel and rail surfaces at the contact region. The shape of the contact area is assumed to be elliptical. The ratio of the contact ellipse semi-axes is equal to the ratio of two non-dimensional contact area coefficients, known as m and n coefficients. Hertz presented a table of these two coefficients, determined as a function of an angular parameter, θ. Most railroad vehicle dynamic codes use this table with online interpolation to determine the contact ellipse semi-axes. Recently, it was found that this original table may be too coarse, and that more data points are needed within the table for solving the wheel/rail contact accurately. This paper discusses the effect of the accuracy of the m and n coefficients in solving for wheel/rail contact, and demonstrates this effect with two numerical examples that show the resulting differences in the dynamic behavior of railroad vehicles dependent on this accuracy. A new table with more data points is presented that is recommended for use in railroad vehicle dynamic codes that employ the Hertzian contact for solving the wheel/rail contact interaction. This modified table was originally derived by Jean-Pierre Pascal as a part of collaborative research between the Federal Railroad Administration (FRA) and the French Ministry of Transportation.

Simultaneous Measurement of Surface Topography and Friction Force by a Single-Head Lateral Force Microscope

1995 ◽  
Vol 117 (2) ◽  
pp. 334-340 ◽  
Author(s):  
C.-J. Lu ◽  
Zhaoguo Jiang ◽  
D. B. Bogy ◽  
T. Miyamoto
Keyword(s):  
Friction Coefficient ◽  
Surface Topography ◽  
Friction Force ◽  
Rotation Angle ◽  
Point Contact ◽  
Lateral Force ◽  
Wear Depth ◽  
Optical Head ◽  
Lateral Force Microscope ◽  
Normal Deflection

Although friction force measurements using one sensor to detect both the normal deflection and rotation angle of a scanning probe are convenient and popular, the critical issues regarding the calibration of the instruments have not been fully studied. A Lateral Force Microscope (LFM), modified from the Point Contact Microscope (PCM), is used to simultaneously measure the surface topography and friction force. An optical head is used to measure the normal bending deflection and rotation angle of the cantilever that carries the diamond tip. Emphasis is put on the development of reliable calibration procedures for obtaining the normal deflection and rotation sensitivities of the optical head as well as the spring constants in the bending and torsion modes. The friction loop, which is essential for friction measurements, is investigated in detail. The LFM is used to measure a two-phase composite to show its ability to distinguish different materials on a surface. Wear tests on a single-crystal silicon <100> surface show different friction coefficient regimes, depending on the applied load. For small loads, there is no wear and the friction coefficient is constant. For larger loads, the friction coefficient and wear depth increase with normal load.

The Influence of Friction Coefficient on Tenon/Groove Contact Performance in Nickel-Based Turbine Blade-Disc

2014 ◽  
Vol 940 ◽  
pp. 74-80 ◽  
Author(s):  
Guo Cai Zhou ◽  
Zhi Xun Wen ◽  
Zhu Feng Yue ◽  
Yu Fen Gao
Keyword(s):  
Fatigue Life ◽  
Friction Coefficient ◽  
Contact Stress ◽  
Crystallographic Orientation ◽  
Contact Region ◽  
Complex Loading ◽  
Plastic Slip ◽  
Rate Dependent ◽  
Stress Fatigue ◽  
The Relationship

This paper presented the influence of crystallographic orientation and friction coefficient on the contact stress and fatigue life in the tenon/groove contact region. A rate-dependent crystallographic plastic slip theory was used to calculate the contact stress and fatigue life in [001], [011] and [111] orientations. In the calculation, complex loading conditions and different friction coefficients of 0, 0.2, 0.4, 0.6, 0.8 and 1.0 were taken into account in tenon/groove. Then the relationship between contact stress, fatigue life and friction coefficient was discussed. Simulation results show that: friction coefficient and crystallographic orientation have significant effect on contact stress and fatigue life. Contact stress in [001], [011] and [111] orientation increases with increasing friction coefficient generally. For [001] and [011] orientation, the fatigue life decreases with increasing friction coefficient firstly. When friction coefficient is 0.4, the fatigue life meets its minimum. Then the fatigue life will increase with increasing friction coefficient. For [111] orientation, the change of fatigue life has no obvious trend, and while friction coefficient exceeds 0.6, the life almost constant.

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