Friction Behavior for Micro-Scale Grooved Crosshatch Pattern under Lubricated Sliding Contact

2007 ◽  
Vol 345-346 ◽  
pp. 769-772 ◽  
Author(s):  
Young Hun Chae
Keyword(s):  
Friction Coefficient ◽  
Bearing Steel ◽  
Friction Reduction ◽  
Surface Pattern ◽  
Stribeck Curve ◽  
Friction Property ◽  
Friction Behavior ◽  
Groove Surface ◽  
Surface Patterns ◽  
Pin On Disk

Some surface patterns of tribological application are an attractive technology of engineered surface. Because of the friction reduction is considered to be necessary for improved efficiency of machine. This study was investigated for the effect of friction property for angles of micro-crosshatch groove surface pattern on bearing steel used pin-on-disk test. We obtain sample which can be fabricated by photolithography process. We discuss the friction property depended on an angle of crosshatch groove surface pattern. We can verify the lubrication mechanism as Stribeck curve which has a relationship between the friction coefficient and a dimensionless parameter under the lubrication condition. It was found that the friction coefficient was related to angle of crosshatch groove pattern on contact surface.

Effect of Size for Micro-Scale Dimples on Surface under Lubricated Sliding Contact

2007 ◽  
Vol 345-346 ◽  
pp. 765-768 ◽  
Author(s):  
Young Hun Chae
Keyword(s):  
Surface Texture ◽  
Sliding Contact ◽  
Friction Reduction ◽  
Stribeck Curve ◽  
Friction Property ◽  
Micro Scale ◽  
Lubrication Condition ◽  
Pin On Disk ◽  
The Relationship ◽  
Lubricated Sliding

The current study investigated the effect of micro-dimple size on reduction friction to understand the potential of friction reduction through micro-scale dimple to fabricate by photolithography on pin-on-disk test using flat-on-flat contact geometry. It was verified that the friction property with respect to the same pitch influences the size of dimple under lubricated sliding contact. Additionally, it was recognized from Stribeck curve that the friction property has a connection with the size of dimple. This can explain the relationship between the friction coefficient and a dimensionless parameter for lubrication condition. The friction property has an effect on the size of surface texture on reduction friction, not only because of the density of dimple, but also because of the ratio of diameter/pitch. A ratio of approximately 0.5 is recommended under the tested friction condition. It is suggested that the ratio of d/p is an important parameter for surface texture design.

On the Prediction of Running-In Behavior in Mixed-Lubrication Line Contact

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Saleh Akbarzadeh ◽  
M. M. Khonsari
Keyword(s):  
Wear Rate ◽  
Load Sharing ◽  
Mixed Lubrication ◽  
Surface Pattern ◽  
Stribeck Curve ◽  
Wear Volume ◽  
Line Contact ◽  
Arithmetic Average ◽  
Volume Wear ◽  
Surface Patterns

A model is presented, which enables one to predict the running-in performance of the rolling/sliding surfaces subjected to mixed-lubrication line contact. The load-sharing concept was used, in which it is assumed that both the fluid film and the asperities contribute in carrying the imposed load. The plastic deformation of asperities during the running-in is taken into consideration. In the application of the load-sharing method, it is often assumed that asperity heights have a Gaussian distribution. This assumption has been relaxed in this model. Prediction results for the variation in the arithmetic average of asperity heights (Ra) during the running-in period for contact of two rollers are compared with published experimental data. Also presented are the results for the variation in wear volume, wear rate, and friction coefficient during the running-in period. The effect of surface pattern, speed, and load on the running-in behavior is studied. The steady-state wear rate for different surface patterns calculated from this model is compared with the wear rate predicted by the thermal desorption model, and the results are in agreement both in trend and magnitude. The effect of running-in on the Stribeck curve for different surface pattern is discussed.

scholarly journals On the Microstructural, Mechanical and Tribological Properties of Mo-Se-C Coatings and Their Potential for Friction Reduction against Rubber

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1336
Author(s):  
Jorge Caessa ◽  
Todor Vuchkov ◽  
Talha Bin Yaqub ◽  
Albano Cavaleiro
Keyword(s):  
Carbon Content ◽  
Friction And Wear ◽  
Current Mode ◽  
Friction Reduction ◽  
Transition Metal Dichalcogenide ◽  
Butadiene Rubber ◽  
Wear Rates ◽  
Mechanical And Tribological Properties ◽  
The Coefficient Of Friction ◽  
Pin On Disk

Friction and wear contribute to high energetic losses that reduce the efficiency of mechanical systems. However, carbon alloyed transition metal dichalcogenide (TMD-C) coatings possess low friction coefficients in diverse environments and can self-adapt to various sliding conditions. Hence, in this investigation, a semi-industrial magnetron sputtering device, operated in direct current mode (DC), is utilized to deposit several molybdenum-selenium-carbon (Mo-Se-C) coatings with a carbon content up to 60 atomic % (at. %). Then, the carbon content influence on the final properties of the films is analysed using several structural, mechanical and tribological characterization techniques. With an increasing carbon content in the Mo-Se-C films, lower Se/Mo ratio, porosity and roughness appeared, while the hardness and compactness increased. Pin-on-disk (POD) experiments performed in humid air disclosed that the Mo-Se-C vs. nitrile butadiene rubber (NBR) friction is higher than Mo-Se-C vs. steel friction, and the coefficient of friction (CoF) is higher at 25 °C than at 200 °C, for both steel and NBR countersurfaces. In terms of wear, the Mo-Se-C coatings with 51 at. % C showed the lowest specific wear rates of all carbon content films when sliding against steel. The study shows the potential of TMD-based coatings for friction and wear reduction sliding against rubber.

scholarly journals Relationship between the real contact behavior and tribological characteristics of cotton fabric

Friction ◽  
2020 ◽  
Author(s):  
Rongxin Chen ◽  
Jiaxin Ye ◽  
Wei Zhang ◽  
Jiang Wei ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Contact Area ◽  
Dynamic Change ◽  
Tribological Characteristics ◽  
Real Contact Area ◽  
Cotton Fibers ◽  
Friction Behavior ◽  
Contact Behavior ◽  
The Real ◽  
Real Contact

Abstract The tribological characteristics of cotton fibers play an important role in engineering and materials science, and real contact behavior is a significant aspect in the friction behavior of cotton fibers. In this study, the tribological characteristics of cotton fibers and their relationship with the real contact behavior are investigated through reciprocating linear tribotesting and real contact analysis. Results show that the friction coefficient decreases with a general increase in load or velocity, and the load and velocity exhibit a co-influence on the friction coefficient. The dynamic change in the real contact area is recorded clearly during the experiments and corresponds to the fluctuations observed in the friction coefficient. Moreover, the friction coefficient is positively correlated with the real contact area based on a quantitative analysis of the evolution of friction behavior and the real contact area at different loads and velocities. This correlation is evident at low velocities and medium load.

An improved nonlinear model considering relative velocity for the friction behavior between untwisted glass-fiber tow and roller

2021 ◽  
pp. 004051752110308
Author(s):  
Yang Liu ◽  
Zhong Xiang ◽  
Xiangqin Zhou ◽  
Zhenyu Wu ◽  
Xudong Hu
Keyword(s):  
Friction Coefficient ◽  
Glass Fiber ◽  
Relative Velocity ◽  
Friction Model ◽  
Woven Fabric ◽  
Test Results ◽  
Application Process ◽  
Friction Behavior ◽  
Improved Model

Friction between the tow and tool surface normally happens during the tow production, fabric weaving, and application process and has an important influence on the quality of the woven fabric. Based on this fact, this paper studied the influence of tension and relative velocity on the three kinds of untwisted-glass-fiber tow-on-roller friction with a Capstan-based test setup. Furthermore, an improved nonlinear friction model taking both tension and velocity into account was proposed. According to statistical test results, firstly, the friction coefficient was found to be positively correlated with tension and relative velocity. Secondly, tension and velocity were complementary on the tow-on-roller friction behavior, with neither being superior to the other. Thirdly, an improved model was found to present well the nonlinear characteristics between friction coefficient and tension and velocity, and predicational results of the model were found to agree well with the observations from Capstan tests.

A novel technique for modeling friction behavior in knitted fabric simulation

2017 ◽  
Vol 29 (6) ◽  
pp. 776-792
Author(s):  
Vajiha Mozafary ◽  
Pedram Payvandy
Keyword(s):  
Friction Coefficient ◽  
Uniform Distribution ◽  
Friction Force ◽  
Experimental Result ◽  
Knitted Fabric ◽  
Friction Behavior ◽  
Content Type ◽  
Novel Technique ◽  
Fabric Structure ◽  
Fabric Surface

Purpose Fabric-object friction force is a fundamental factor in cloth simulation. A large number of parameters influence the frictional properties of fabrics such as fabric structure, yarn structure, and inherent properties of component fibers. The purpose of this paper is to propose a novel technique for modeling fabric-object friction force in knitted fabric simulation based on the mass spring model. Design/methodology/approach In this technique, unlike other studies, distribution of friction coefficient over the fabric surface is not uniform and depends on the fabric structure. The main reason for considering non-uniform distribution is that in various segments of fabric, contact percent of fabric-object is different. Findings The proposed technique and common methods based on friction coefficient uniform distribution are used to simulate the frictional behavior of knitted fabrics. The results show that simulation error values for proposed technique and common methods are 2.7 and 9.4 percent as compared with the experimental result, respectively. Originality/value In the existing methods of the friction force modeling, the friction coefficient of fabric is assumed uniform. But this assumption is not correct because fabric does not have an isotropic structure. Thus in this study, the friction coefficient distribution is considered based on fabric structure to achieve more of realistic simulations.

Structural and Tribological Properties of TiC/C/Ag Coatings in Vacuum and Ambient Environments

2001 ◽  
Vol 697 ◽  
Author(s):  
Jose L. Endrino ◽  
Jose J. Nainaparampil ◽  
James E. Krzanowski
Keyword(s):  
Carbon Content ◽  
Laser Energy ◽  
High Vacuum ◽  
Ambient Conditions ◽  
Friction Behavior ◽  
Cross Sectional ◽  
Reduced Modulus ◽  
Custom Made ◽  
Disk Friction ◽  
Pin On Disk

AbstractTiC/C/Ag coatings were deposited by magnetron sputtering pulsed laser deposition (MSPLD) combining sputtering from a custom made Ti-Ag (60:40) target with the ablation of carbon. Energy disperse spectroscopy (EDS) was used to determine the elemental composition, and x-ray diffraction (XRD) and cross-sectional scanning electron microscopy (XSEM) to examine the structure of the films. Hardness and reduced modulus measurements were acquired using a nanoindentation technique. The pin-on-disk friction test was used to study the friction behavior of the deposited samples in high vacuum and ambient conditions. Variations in the laser energy and the power of the sputtering gun yielded a set of samples with carbon content that ranged from 15.0 to 95.6 percent. The hardest samples with the highest reduced modulus were those with a moderate carbon content and that were shown to form a titanium carbide phase. Tribological results indicated that there is an optimum composition of a TiC/C/Ag coating (~25 at.% carbon) for which it can be reversible and provide lubrication in both ambient and vacuum.

Predicting the wear coefficient and friction coefficient in dry point contact using continuum damage mechanics

2018 ◽  
Vol 233 (3) ◽  
pp. 447-455 ◽  
Author(s):  
Sahar Ghatrehsamani ◽  
Saleh Akbarzadeh
Keyword(s):  
Friction Coefficient ◽  
Damage Mechanics ◽  
Point Contact ◽  
Continuum Damage Mechanics ◽  
Continuum Damage ◽  
Wear Coefficient ◽  
Mechanics Model ◽  
Pin On Disk ◽  
Disk Test ◽  
The Continuum

Wear coefficient and friction coefficient are two of the key parameters in the performance of any tribo-system. The main purpose of the present research is to use continuum damage mechanics to predict wear coefficient. Thus, a contact model is utilized that can be used to obtain the friction coefficient between the contacting surfaces. By applying this model to the continuum damage mechanics model, the wear coefficient between dry surfaces is predicted. One of the advantages of using this model is that the wear coefficient can be numerically predicted unlike other methods which highly rely on experimental data. In order to verify the results predicted by this model, tests were performed using pin-on-disk test rig for several ST37 samples. The results indicated that the wear coefficient increases with increasing the friction coefficient.

Comparison in Tribological Properties of YBa2Cu3OX/Ag and Bi2Sr2CaCu2OX/Ag Self-Lubricating Composites

2011 ◽  
Vol 291-294 ◽  
pp. 34-40
Author(s):  
Hua Tang ◽  
Wen Jing Li ◽  
Chang Sheng Li
Keyword(s):  
Friction Coefficient ◽  
Tribological Properties ◽  
Room Temperature ◽  
Superconducting Transition ◽  
Friction Test ◽  
Average Value ◽  
Structure And Morphology ◽  
Disk Friction ◽  
Pin On Disk ◽  
Self Lubricating Composites

The YBa2Cu3Ox/Ag and Bi2Sr2CaCu2Ox/Ag self-lubricating composites were prepared using powder metallurgic method. The crystal structure and morphology of the as-synthesized samples were characterized by XRD and SEM. The YBa2Cu3Ox/Ag and Bi2Sr2CaCu2Ox/Ag self-lubricating composites were found to compose of superconductor phase and Ag phase. The tribological properties from ultra-low temperature to room temperature of the composites were studied by pin-on-disk friction test. It was found that the friction coefficients of pure YBa2Cu3Ox(YBCO) and Bi2Sr2CaCu2Ox(BSCCO) were both dropped abruptly when the temperature cooled below the superconducting transition temperature. At room temperature, the friction coefficient of pure YBa2Cu3Oxis 0.68~0.95, when mixing 15wt% Ag, the friction coefficient of the sample decreased to the lowest value 0.11. The friction coefficient of pure Bi2Sr2CaCu2Ox is 0.15~0.17, When Ag content reach 10wt%, the coefficient was lowest (average value is 0.13). The addition of appropriate amount of Ag obviously improve the tribological property of YBCO, while only slightly meliorate that of BSCO. On the other hand, the YBCO/Ag composites exhibit better tribological properties than BSCCO/Ag composites at higher load under the same experimental condition.

Friction reduction in EHL contacts by surface microtexturing – tribological performance, manufacturing and tailored design

2019 ◽  
Vol 71 (8) ◽  
pp. 986-990 ◽  
Author(s):  
Stephan Tremmel ◽  
Max Marian ◽  
Michael Zahner ◽  
Sandro Wartzack ◽  
Marion Merklein
Keyword(s):  
Product Life Cycle ◽  
Structural Parameters ◽  
Surface Texturing ◽  
Friction Reduction ◽  
Forming Process ◽  
Friction Behavior ◽  
Holistic View ◽  
Content Type ◽  
Efficient Manufacturing ◽  
Tailored Design

Purpose This paper aims to derive tailor-made microtextures for elastohydrodynamically lubricated (EHL) contacts under consideration of manufacturing possibilities. Design/methodology/approach Component tests were used for the evaluation of the influence of surface texturing on the friction behavior in the cam/tappet contact. Furthermore, the manufacturing possibilities and limitations of a combined μEDM and micro-coining process and the feasibility of integration into a forming process were studied. Finally, a methodology based on transient EHL simulations and a meta-model of optimal prognosis was exemplarily used for microtexture optimization. Findings It was found that surface texturing in EHL contacts with high amount of sliding is promising. Moreover, the combination of μEDM and micro coining and the integration into established production processes allow the manufacturing of microtextures with desirable structural parameters and sufficient accuracy. Originality/value This paper gives a holistic view on surface microtexturing over several phases of the product life cycle, from the design, over efficient manufacturing to application-related testing.

Sign in / Sign up

Export Citation Format

Share Document