scholarly journals Effect of Bulk Current Density on Tribological Properties of Fe-W, Co-W and Ni-W Coatings

2015 ◽  
Author(s):  
S.A. Silkin ◽  
A.V. Gotelyak ◽  
N. Tsyntsaru ◽  
A.I. Dikusar ◽  
R. Kreivaitis ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Coefficient Of Friction ◽  
Current Density ◽  
Dry Friction ◽  
Scratch Test ◽  
Tribological Behaviour ◽  
The Coefficient Of Friction ◽  
Current Densities ◽  
Scratch Tests ◽  
The Given

Evaluation of tribological behaviour of Fe-W, Ni-W and Co-W coatings produced by electrodeposition at various bulk current densities (BCD) was under investigation in the given study. BCD does not have essential effect on the microhardness and wear characteristics of Fe-W and Co-W coatings. But the scratch tests reveal the presence of such influence. These tests showed superior wear resistance for the coatings obtained at low BCD. It was found that BCD has influence on wear resistance of Ni-W coatings under dry friction conditions. The BCD also has an influence on the coefficient of friction of Fe-W and Ni-W coatings at dry friction conditions. However, such an effect is opposite to that, observed at the scratch test.

Effect of Directionality of Grinding Marks on Friction at Different Surface Roughness Using Inclined Scratch Test

2005 ◽  
Author(s):  
Pradeep L. Menezes ◽  
Kishore ◽  
Satish V. Kailas
Keyword(s):  
Surface Roughness ◽  
Coefficient Of Friction ◽  
Scratch Test ◽  
Layer Formation ◽  
Transfer Layer ◽  
Frictional Behavior ◽  
Mating Surface ◽  
The Coefficient Of Friction ◽  
Angle Effect ◽  
Scratch Tests

Surface topography of a tool plays an important role as it predominantly controls the frictional behavior at the interface. In the present study, Inclined Scratch Tester was used to understand the effect of directionality of surface grinding marks on coefficient of friction and transfer layer formation. EN8 steel flats were ground to attain different surface roughness with unidirectional grinding marks. Then Al-Mg alloy pins were scratched against the prepared EN8 steel flats. Grinding angle (angle between direction of scratch and grinding marks) was varied between 0° and 90° during the scratch tests. It was observed that the coefficient of friction and transfer layer formation depend primarily on the directionality of grinding marks of the harder mating surface, and independent of surface roughness of harder mating surface. The grinding angle effect on coefficient of friction was attributed to the variation of plowing component of friction with grinding angle.

ANALYSIS OF FRACTURE AND WEAR RESISTANCE OF ZrN COATINGS

Tribologia ◽  
2018 ◽  
Vol 273 (3) ◽  
pp. 39-45 ◽  
Author(s):  
Kinga CHRONOWSKA-PRZYWARA ◽  
Marcin KOT
Keyword(s):  
Wear Resistance ◽  
Coefficient Of Friction ◽  
Coating Thickness ◽  
Elasticity Modulus ◽  
Scratch Test ◽  
The Coefficient Of Friction ◽  
Steel Substrates ◽  
Resistance Tests ◽  
Ball On Disc

The article presents the results of mechanical and tribological studies of ZrN coatings that allowed the determination of their hardness, elasticity modulus, and scratch and wear resistance. Tests were carried out for 1, 1.4, and 2 μm thick ZrN coatings deposited on X5CrNi18-10 austenitic steel substrates by PVD technology. Hardness and Young's modulus of coatings, evaluated by nanoindentation, were within the 26–32 GPa, and 330–360 GPa ranges, respectively. Analysis of the adhesion of the coating to the substrate was carried out based on the results of the scratch test. The highest critical load values of LC1 and LC2 were measured for the 1.4 μm thick coating. Tribological tests performed using a ball-on-disc tribotester showed that the wear resistance increases with coating thickness. This was accompanied by a reduction of the coefficient of friction from 0.22 to 0.17.

Tribometer for Dry Friction Measurement

1999 ◽  
Author(s):  
Marc Brandl ◽  
Friedrich Pfeiffer
Keyword(s):  
Coefficient Of Friction ◽  
Dry Friction ◽  
Stribeck Curve ◽  
Body System ◽  
Friction Measurement ◽  
Detailed Model ◽  
The Coefficient Of Friction ◽  
Simulation Results ◽  
Multi Body

Abstract This paper deals with the measurement of dry friction. A tribometer was developed in order to identify both the sticking and the sliding coefficient of friction. The aim was to determine the so called Stribeck-curve of any material in contact. The design of the plant is presented. Avoiding errors in recalculating the coefficient of friction, a detailed model of the plant as a multi body system with motor feedback was generated. Advantages of the tribometer are shown in simulations. Some results of measurements in comparison with simulation results are presented.

Effect of particle size on mechanical properties and tribological behaviour of aluminium/fly ash composites

2012 ◽  
Vol 19 (3) ◽  
pp. 247-253 ◽  
Author(s):  
Krishnan Ravi Kumar ◽  
Kothavady Mylsamy Mohanasundaram ◽  
Ganesan Arumaikkannu ◽  
Ramanathan Subramanian
Keyword(s):  
Tensile Strength ◽  
Wear Resistance ◽  
Fly Ash ◽  
Ultimate Tensile Strength ◽  
Coefficient Of Friction ◽  
Fine Particles ◽  
Dry Sliding Wear ◽  
Tribological Behaviour ◽  
Weight Percentage ◽  
Pin On Disc

AbstractIn the present study, aluminium alloy (A380) composites containing 3, 6, 9 and 12 weight percentage of fly ash particles were fabricated by liquid metallurgy technique. Three different size ranges of fly ash particles (50–75 μm, 75–103 μm and 103–150 μm) were used. The composites were evaluated for hardness, tensile strength, density, dry sliding wear and frictional behaviour. Pin-on disc apparatus was used to conduct wear tests at loads of 20, 30 and 40 N at a sliding speed of 3 m/s for a constant period of 10 min. Results showed that hardness, ultimate tensile strength, wear resistance and coefficient of friction were superior in composites reinforced with coarse fly ash particles (103–150 μm) compared to composites with fine particles. The hardness, ultimate tensile strength and wear resistance increased, whereas the coefficient of friction and density decreased with the increase in weight percentage of fly ash. Wear resistance and coefficient of friction decreased with increase in applied load. Scanning electron microscope investigations of worn-out samples were carried out to study the progress of wear.

Tribological behaviour of A390/Grp metal—matrix composites fabricated using a combination of rheocasting and squeeze casting techniques

2008 ◽  
Vol 222 (2) ◽  
pp. 257-265 ◽  
Author(s):  
T S Mahmoud
Keyword(s):  
Wear Resistance ◽  
Sliding Wear ◽  
Squeeze Casting ◽  
Dry Sliding Wear ◽  
Matrix Composites ◽  
Tribological Behaviour ◽  
Wear Performance ◽  
The Coefficient Of Friction ◽  
Steel Disc ◽  
A390 Alloy

The dry sliding wear performance of hypereutectic A390 Al—Si alloy reinforced with graphite particulates (Grp) was investigated. Composites containing 4 and 8 wt% of Grp were produced by rheocasting technique followed by squeeze casting. Pins of the materials were rubbed against a 316 stainless steel disc using pin-on-ring type apparatus under various loads and speeds. It has been observed that both wear rate and the coefficient of friction of the composites decreased considerably with Grp additions. The A390/Grp composites exhibited higher wear resistance than those obtained for the monolithic A390 alloy. The formation of the hard tribo-layer on the surface of the composites assisted in increasing the wear resistance of these materials. It is believed that the reduction of the friction coefficient is attributed the presence of the graphite layers within the tribo-layer.

The Influence of Surface Roughness on the Mechanism of Friction

1970 ◽  
Vol 92 (2) ◽  
pp. 264-272 ◽  
Author(s):  
T. Tsukizoe ◽  
T. Hisakado
Keyword(s):  
Surface Roughness ◽  
Metal Surface ◽  
Coefficient Of Friction ◽  
Dry Friction ◽  
Metal Surfaces ◽  
Roughness Effects ◽  
Real Area Of Contact ◽  
The Coefficient Of Friction ◽  
Tangential Forces ◽  
Soft Metal

A study was made of surface roughness effects on dry friction between two metals, assuming that the asperities are cones of the slopes which depend on the surface roughness. The theoretical explanations were offered for coefficients of friction of the hard cones and spheres ploughing along the soft metal surface. A comparison of calculated values based on these with experimental data shows good agreement. Moreover, theoretical discussion was carried out of surface roughness effects on dry friction between two metal surfaces on the basis of the analyses of the frictional mechanism for a hard slider on the metal surface. The theoretical estimation of the coefficient of friction between two metal surfaces can be carried out by using the relations between the surface roughness and the slopes of the asperities, and the coefficient of friction due to the adhesion at the interface. The experiments also showed that when two metal surfaces are first loaded normally and then subjected to gradually increasing tangential forces, real area of contact between them increases and the maximum tangential microslip of them increases with the increase of the surface roughness.

Influence of Surface Roughness on Friction and Contact Resistance in Sliding Electrical Contacts

2007 ◽  
Author(s):  
Dinesh G. Bansal ◽  
Jeffrey L. Streator
Keyword(s):  
Surface Roughness ◽  
Contact Resistance ◽  
Coefficient Of Friction ◽  
Electrical Contact ◽  
Electrical Current ◽  
Electrical Contacts ◽  
Sliding Electrical Contacts ◽  
The Coefficient Of Friction ◽  
Current Densities

An experiment is conducted to investigate the role of surface roughness on the coefficient of friction and contact resistance of sliding electrical contacts. A hemispherical pin is sliding along both smooth and rough 2-meter rail surface. Tests are performed at both low and moderate sliding speed and for a range of electrical current densities, ranging from 0 to about 12 GA/m2. It was found that surface roughness had a significant influence on the coefficient of friction, with the smoother surfaces exhibiting higher coefficients of friction. Contact resistance, on the other hand, did not show as strong an effect of surface roughness, except for a few parameter combinations. At the higher current densities studied (>10 GA/m2), it was found that the contact resistance values tended to be on the order of 1 mΩ, independent of load, speed and roughness. This convergence may be due to presence of liquid metal film at the interface, which established ideal electrical contact.

scholarly journals Tribological Behaviour of Sputter Coated ZnO Thin Films

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Ahalaptiya H Jayatissa ◽  
◽  
Omer Ahmed ◽  
Bodhi R Manu ◽  
Adam M Schroeder
Keyword(s):  
Heat Treatment ◽  
Coefficient Of Friction ◽  
Testing Machine ◽  
Rf Magnetron Sputtering ◽  
Zno Films ◽  
Work Piece ◽  
Tribological Behaviour ◽  
Deposition Power ◽  
The Coefficient Of Friction ◽  
Pin On Disk

The tribological properties of ZnO thin film coated on an aluminium work piece by RF magnetron sputtering were studied as a function of deposition power, substrate coating temperature, heat treatment and rotation speed. The variation in the coefficient of friction of ZnO films produced under various levels of coating parameters and conditions were experimentally determined using a pin-on-disk tribometer. The results showed that with change in deposition conditions and heat treatment, there are significant microstructural changes in ZnO films, which affect the coefficient of friction. The hardness of the prepared films was also tested using a Vickers Hardness testing machine. There was a consistent and considerable decrease in the friction coefficient of the aluminium working piece after ZnO coating. It is found that the ZnO can be used as a low friction coating material for components working under oxidative and high temperature environments.

Development of Antifriction Materials Based on Polytetrafluoroethylene with Carbon Fibers and Tungsten Disulfide

2020 ◽  
Vol 992 ◽  
pp. 745-750
Author(s):  
A.P. Vasilev ◽  
T.S. Struchkova ◽  
A.G. Alekseev
Keyword(s):  
Wear Resistance ◽  
Polymer Composites ◽  
Carbon Fibers ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Relative Elongation ◽  
Tungsten Disulfide ◽  
Degree Of Crystallinity ◽  
Mechanical And Tribological Properties ◽  
The Coefficient Of Friction

This paper presents the results from the investigation of effect the carbon fibers with tungsten disulfide on the mechanical and tribological properties of PTFE. Is carried out a comparison of mechanical and tribological properties of polymer composites PTFE-based with carbon fibers and PTFE with complex filler (carbon fibers with tungsten disulfide). It is shown that at a content of 8 wt.% CF+1 wt.% WS2 in PTFE, wear resistance increases significantly while maintaining the tensile strength, relative elongation at break and low coefficient of friction at the level of initial PTFE. The results of X-ray analysis and investigation of SEM supramolecular structure and friction surfaces of PTFE and polymer composites are presented. It is shown that the degree of crystallinity of polymer composites increases in comparison with the initial PTFE. The images of scanning electron microscope reveal that particles of tungsten disulfide concentrating on the friction surface is likely responsible to a reduction in the coefficient of friction and increase the wear resistance of PTFE-based polymer composites with complex fillers.

The Influence of Nano-Silica on the Wear Resistance of Ceramic – Polymer Composites Intended for Dental Fillings

2009 ◽  
Vol 151 ◽  
pp. 135-138
Author(s):  
Joanna Siejka-Kulczyk ◽  
Joanna Mystkowska ◽  
Małgorzata Lewandowska ◽  
Jan R. Dabrowski ◽  
Krzysztof Jan Kurzydlowski
Keyword(s):  
Wear Resistance ◽  
Polymer Composites ◽  
Coefficient Of Friction ◽  
Volume Fraction ◽  
Tooth Enamel ◽  
Nano Particles ◽  
Human Tooth ◽  
Nano Silica ◽  
The Coefficient Of Friction ◽  
Composite Samples

Ceramic – polymer composites based on acrylic (bis–GMA) and urethane – methacrylate (UM) resins with a 60 % total volume fraction of filler consisting of micro particles of glass and nano-particles of silica were fabricated. The nano-silica contents were: 0, 10, 20 vol. %. The composite samples were subjected to wear tests using an occlusion simulator tester which applies reciprocating movement and cyclic loading on the test material. This method of testing provides some similarity to the masticatory pattern occurring in the mouth during eating. The enamel of a human tooth was used as a counter-sample. The coefficient of friction was determined and the wear resistance of the composite samples containing the various nano-silica contents was established. In addition, the relative influence of the composite composition on the rate of wear of the human tooth enamel was estimated. The results of the study indicate that the addition of nano-silica significantly improves the wear resistance of the ceramic – polymer composites and reduces the wear of enamel. It was found that the addition of nano-silica has no influence on the coefficient of friction. It was also established that composites based on UM resin show better wear resistance than those based on a mixture of bis-GMA and TEGDMA resin.

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