The Influence of the Temperature in Severe Wear of Copper Contact Wire/carbon Strip under Electric Current

2011 ◽  
Vol 71-78 ◽  
pp. 3653-3656
Author(s):  
Tao Ding ◽  
Guang Xiong Chen ◽  
Zeng Gang Xiong ◽  
Li Xie ◽  
Chuan Xue Wu
Keyword(s):  
Friction Coefficient ◽  
Electric Current ◽  
Experimental Tests ◽  
Electrical Current ◽  
Severe Wear ◽  
Contact Wire ◽  
Thermal Wear ◽  
Current Passage ◽  
Pin On Disc ◽  
Contact Couple

A series of experimental tests were carried out using copper contact wire rubbing against carbon strip under electric current on a pin-on-disc test. The aim to experiment can be understand the roles of the thermal wear in severe wear of copper/carbon strip under electrical current passage. During testing, the contact temperature and friction coefficient were recorded. The wear volumes of carbon strip specimens were measured. The results indicate that the temperature rise of contact couple with and without electric current is distinctly different. And the friction coefficient increases firstly due to the accumulation of wear debris, and then decreases with the increasing of electric current due to the accumulation of electric heat and friction heat on contact interface. It can be found that the wear volumes of carbon strip samples with electric current are larger than those without electrical current. Several thermal wear tests were conducted to study the influence of the temperature on the wear of carbon strip samples. The result indicates that thermal wear, oxidation wear and abrasive wear are a main mechanism for the severe wear of carbon strip samples.

The Role of Electric Current on Friction and Wear Behaviors of the Carbon Strip/Copper Contact Wire

2011 ◽  
Vol 80-81 ◽  
pp. 178-181
Author(s):  
Tao Ding ◽  
G.X. Chen ◽  
Z.G. Xiong ◽  
Li Xie ◽  
C.X. Wu
Keyword(s):  
Friction Coefficient ◽  
Electric Current ◽  
Friction And Wear ◽  
Sliding Friction ◽  
Material Transfer ◽  
Friction Process ◽  
Contact Wire ◽  
Pin On Disc ◽  
Worn Surface

A serial of experiment studies on the friction and wear behaviors of the carbon strip/copper contact wire under the electric current were carried on the pin-on-disc tester. The results indicated that the tribology performances were remarkably affected by the electric current. The friction coefficient decreases with an increase of electric current. However, the were volume increases with increasing of electric current, and the worn surface of carbon strip become severer and severer with the increasing electric current. Therefore, the electric current play roles of lubrication and accelerating wear in the process of electrical sliding friction. By the analysis of EDX, it is seen that the oxide wear exists in electrical sliding friction process. Observing the worn surfaces of copper pan sample, it is found that the electric current increases the material transfer of carbon strip.

Effect of Arc Discharge on Friction and Wear Behaviors of Stainless Steel/Copper-Impregnated Metalized Carbon Couple under Electric Current

2010 ◽  
Vol 150-151 ◽  
pp. 1364-1368 ◽  
Author(s):  
Tao Ding ◽  
Guang Xiong Chen ◽  
Ming Xue Shen ◽  
Min Hao Zhu ◽  
Wei Hua Zhang
Keyword(s):  
Stainless Steel ◽  
Electric Current ◽  
Friction And Wear ◽  
Arc Discharge ◽  
Arc Erosion ◽  
Pin On Disc ◽  
Contact Couple ◽  
Worn Surface ◽  
Oxidation Wear ◽  
Friction And Wear Tests

Friction and wear tests of stainless steel rubbing against copper-impregnated metalized carbon with electric current were carried on the pin-on-disc tester. The result indicates that arc discharge occurs in the process of experiments, and the intensity of arc discharge of interface increases with increasing of electric current and sliding velocity. As increasing of the arc discharge intensity, friction coefficient shows a tendency of slightly increase. While the rate of copper-impregnated metalized carbon material increase significantly with the increase of arc discharge intensity. Through observing the worn surface morphology of pin samples, it is found that the abrasive wear is dominant at small arc discharge due to worn particles and arc ablation craters, but arc erosion and oxidation wear are the main wear mechanisms in condition of large arc discharge due to arc discharge and its producing high temperature. The materials transfer of contact couple occurs in the process of friction and wear.

Experimental study on the temperature of the contact strip in sliding electric contact

2017 ◽  
Vol 231 (10) ◽  
pp. 1268-1275 ◽  
Author(s):  
GX Chen ◽  
Y Hu ◽  
BJ Dong ◽  
HJ Yang ◽  
GQ Gao ◽  
...  
Keyword(s):  
Electric Current ◽  
Normal Force ◽  
Experimental Tests ◽  
Wear Volume ◽  
Test Results ◽  
Electric Contact ◽  
Sliding Speed ◽  
Factors Affecting ◽  
Contact Wire ◽  
Sliding Electric Contact

Using a ring-on-block tester with AC, the authors accomplished several experimental tests on the temperature of the contact wire and strip in sliding electric contact. In the test, the temperature of the samples, arc voltage, electric current, and wear volume of the strip were collected. Influences of the normal force, sliding speed, and electric current on the temperature of the contact wire and strip were studied. Test results show that the temperature of the carbon strip increases with the increasing of sliding speed and electric current or the decreasing of normal force. The strip wear rate is linearly related with the temperature of the strip. Moreover, the factors affecting the strip temperature were also discussed.

scholarly journals Experimental Methods for Measuring the Viscous Friction Coefficient in Hydraulic Spool Valves

2021 ◽  
Vol 13 (13) ◽  
pp. 7174
Author(s):  
Massimo Rundo ◽  
Paolo Casoli ◽  
Antonio Lettini
Keyword(s):  
Friction Coefficient ◽  
Viscous Friction ◽  
Experimental Tests ◽  
Experimental Methods ◽  
Displacement Transducer ◽  
A Posteriori ◽  
Displacement Control ◽  
Spool Valves ◽  
The University ◽  
Good Agreement

In hydraulic components, nonlinearities are responsible for critical behaviors that make it difficult to realize a reliable mathematical model for numerical simulation. With particular reference to hydraulic spool valves, the viscous friction coefficient between the sliding and the fixed body is an unknown parameter that is normally set a posteriori in order to obtain a good agreement with the experimental data. In this paper, two different methodologies to characterize experimentally the viscous friction coefficient in a hydraulic component with spool are presented. The two approaches are significantly different and are both based on experimental tests; they were developed in two distinct laboratories in different periods of time and applied to the same flow compensator of a pump displacement control. One of the procedures was carried out at the Fluid Power Research Laboratory of the Politecnico di Torino, while the other approach was developed at the University of Parma. Both the proposed methods reached similar outcomes; moreover, neither method requires the installation of a spool displacement transducer that can significantly affect the results.

scholarly journals The Impact of Heat Treatment on the Behavior of a Hot-Dip Zinc Coating Applied to Steel During Dry Friction

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 660
Author(s):  
Dariusz Jędrzejczyk ◽  
Elżbieta Szatkowska
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Dry Friction ◽  
Zinc Coating ◽  
Pin On Disc ◽  
The One ◽  
The Impact ◽  
Coating Hardness ◽  
Anticorrosion Properties

The analyzed topic refers to the wear resistance and friction coefficient changes resulting from heat treatment (HT) of a hot-dip zinc coating deposited on steel. The aim of research was to evaluate the coating behavior during dry friction after HT as a result of microstructure changes and increase the coating hardness. The HT parameters should be determined by taking into consideration, on the one hand, coating wear resistance and, on the other hand, its anticorrosion properties. A hot-dip zinc coating was deposited in industrial conditions (according EN ISO 10684) on disc-shaped samples and the chosen bolts. The achieved results were assessed on the basis of tribological tests (T11 pin-on-disc tester, Schatz®Analyse device, Sindelfingen, Germany), microscopic observations (with the use of optical and scanning microscopy), EDS (point and linear) analysis, and microhardness measurements. It is proved that properly applied HT of a hot-dip zinc coating results in changes in the coating’s microstructure, hardness, friction coefficient, and wear resistance.

Friction Characteristics with Pin-on-Disc Friction Test on Microstructured Surface Using Whirling Electrical Discharge Texturing

2014 ◽  
Vol 1017 ◽  
pp. 417-422
Author(s):  
Vitchuda Lertphokanont ◽  
Takayuki Sato ◽  
Masahiro Oi ◽  
Minoru Ota ◽  
Keishi Yamaguchi ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Electrical Discharge ◽  
Area Ratio ◽  
Mixed Lubrication ◽  
Optimal Conditions ◽  
Friction Test ◽  
Crater Diameter ◽  
Microstructured Surface ◽  
Pin On Disc ◽  
Lubrication Condition

A microstructured surface was created on a steel surface by whirling electrical discharge texturing (WEDT) since it was considered that the microstructures could act as lubricant reservoirs to assist the formation of a lubricating film, resulting in reduced friction. In this study, friction tests under engine oil were carried out over a range of loads and sliding speeds. In addition, the surface characteristics of the microstructured surface were also investigated to optimize the friction characteristics of the textured surface through pin-on-disc friction tests. It was found that under the mixed lubrication condition near the boundary condition, textured surfaces with texture-area ratio of approximately 6% and a mean crater diameter of 35 μm were considered as the optimal conditions for reducing the friction coefficient. However, a texture-area ratio of approximately 4% and a mean crater diameter of 35 μm were considered as the optimal conditions for reducing the friction coefficient under the mixed lubrication condition near the elastohydrodynamic lubrication condition. It was considered that when the normal load decreased, the lubrication region changed from the mixed lubrication condition to the hydrodynamic lubrication condition, which meant that the actual contact surface area decreased. The decrease in the actual contact surface area with decreasing texture-area ratio led to a reduction in the friction coefficient. Finally, it was clarified that the friction coefficient was reduced under the optimized conditions of the microstructured surface through a pin-on-disc friction test.

INFLUENCE OF NITROGEN FLOW RATE ON FRICTION COEFFICIENT AND SURFACE ROUGHNESS OF TiN COATINGS DEPOSITED ON TOOL STEEL USING ARC METHOD

2007 ◽  
Vol 14 (05) ◽  
pp. 1007-1013 ◽  
Author(s):  
ESAH HAMZAH ◽  
ALI OURDJINI ◽  
MUBARAK ALI ◽  
PARVEZ AKHTER ◽  
MOHD RADZI HJ. MOHD TOFF ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Tool Steel ◽  
Flow Rate ◽  
Physical Vapor Deposition ◽  
Gas Flow ◽  
Cutting Tools ◽  
Gas Flow Rate ◽  
Pin On Disc ◽  
The Coefficient Of Friction

In the present study, the effect of various N 2 gas flow rates on friction coefficient and surface roughness of TiN -coated D2 tool steel was examined by a commercially available cathodic arc physical vapor deposition (CAPVD) technique. A Pin-on-Disc test was carried out to study the Coefficient of friction (COF) versus sliding distance. A surface roughness tester measured the surface roughness parameters. The minimum values for the COF and surface roughness were recorded at a N 2 gas flow rate of 200 sccm. The increase in the COF and surface roughness at a N 2 gas flow rate of 100 sccm was mainly attributed to an increase in both size and number of titanium particles, whereas the increase at 300 sccm was attributed to a larger number of growth defects generated during the coating process. These ideas make it possible to optimize the coating properties as a function of N 2 gas flow rate for specific applications, e.g. cutting tools for automobiles, aircraft, and various mechanical parts.

Research on the delamination wear properties of the pure carbon strip at the high-sliding speed with electric current

2018 ◽  
Vol 70 (1) ◽  
pp. 76-83 ◽  
Author(s):  
Hongjuan Yang ◽  
Lin Fu ◽  
Yanhua Liu ◽  
Weiji Qian ◽  
Bo Hu
Keyword(s):  
Electric Current ◽  
High Speed ◽  
Normal Load ◽  
Copper Wire ◽  
Electrical Current ◽  
Wear Properties ◽  
Sliding Speed ◽  
Content Type ◽  
Delamination Wear ◽  
High Speed Data

Purpose This paper aims to investigate the delamination wear properties of a carbon strip in a carbon strip rubbing against a copper wire at the high-sliding speed (380 km/h) with or without electrical current. Design/methodology/approach The friction and wear properties of a carbon strip in a carbon strip rubbing against a copper wire are tested on the high-speed wear tester whose speed can reach up to 400 km/h. The test data have been collected by the high-speed data collector. The worn surfaces of the carbon strip are observed by the scanning electron microscope. Findings It was found that there was a significant increase of the delamination wear with the decrease of the normal load when the electric current is applied. The size of the flake-like peeling also increases with the decrease of normal load. The delamination wear extends gradually from the edge of the erosion pits to the surrounding area with the decrease of the normal load. However, the delamination wear never appears in the absence of electric current. It is proposed that the decreased normal load and the big electrical current are the major causes of the delamination wear of the carbon strip. Originality value The experimental test at high-sliding speed of 380 km/h was performed for the first time, and the major cause of the delamination was discovered in this paper.

Tribological properties of ultrahigh-molecular-weight polyethylene (UHMWPE) composites reinforced with different contents of glass and carbon fibers

2019 ◽  
Vol 71 (1) ◽  
pp. 22-30 ◽  
Author(s):  
Yanzhen Wang ◽  
Zhongwei Yin
Keyword(s):  
Molecular Weight ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
High Performance ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Content Type ◽  
Ultrahigh Molecular Weight ◽  
Pin On Disc ◽  
Uhmwpe Composites ◽  
Uhmwpe Composite

PurposeThis purpose of this study was to investigate the effects of carbon fiber (CF) and/or glass fiber (GF) fillers on the tribological behaviors of ultrahigh-molecular-weight polyethylene (UHMWPE) composites to develop a high-performance water-lubricated journal bearing material.Design/methodology/approachTribological tests were conducted using a pin-on-disc tribometer using polished GCr15 steel pins against the UHMWPE composite discs under dry conditions with a contact pressure of 15 MPa and a sliding speed of 0.15 m/s. Scanning electron microscopy, laser 3D micro-imaging profile measurements and energy-dispersive X-ray spectrometry were used to analyze the morphologies and elemental distributions of the worn surfaces.FindingsThe results showed that hybrid CF and GF fillers effectively improved the wear resistance of the composites. The fiber fillers decreased the contact area, promoted transfer from the polymers and decreased the interlocking and plowing of material pairs, which contributed to the reduction of both the friction coefficient and the wear rate.Originality/valueThe UHMWPE composite containing 12.5 Wt.% CF and 12.5 Wt.% GF showed the best wear resistance of 2.61 × 10−5mm3/(N·m) and the lower friction coefficient of 0.12 under heavy loading. In addition, the fillers changed the worn surface morphology and the wear mechanism of the composites.

scholarly journals Tribological Properties of Si3N4-hBN Composite Ceramics Bearing on GCr15 under Seawater Lubrication

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 635 ◽  
Author(s):  
Fang Han ◽  
Huaixing Wen ◽  
Jianjian Sun ◽  
Wei Wang ◽  
Yalong Fan ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Tribological Properties ◽  
Photoelectron Spectroscopy ◽  
Dry Friction ◽  
Pure Water ◽  
Water Environment ◽  
Surface Films ◽  
Seawater Lubrication ◽  
Pin On Disc ◽  
Worn Surface

This paper concerns a comparative study on the tribological properties of Si3N4-10 vol% hBN bearing on GCr15 steel under seawater lubrication and dry friction and fresh-water lubrication by using a pin-on-disc tribometer. The results showed that the lower friction coefficient (around 0.03) and wear rate (10−6 mm/Nm) of SN10/GCr15 tribopair were obtained under seawater condition. This might be caused by the comprehensive effects of hydrodynamics and boundary lubrication of surface films formed after the tribo-chemical reaction. Despite SN10/GCr15 tribopair having 0.07 friction coefficient in the pure-water environment, the wear mechanismsits were dominated by the adhesive wear and abrasive wear under the dry friction conditions, and delamination, plowing, and plastic deformation occured on the worn surface. The X-ray photoelectron spectroscopy analysis indicated that the products formed after tribo-chemaical reaction were Fe2O3, SiO2, and B2O3 and small amounts of salts from the seawater, and it was these deposits on the worn surface under seawater lubrication conditions that, served to lubricate and protect the wear surface.

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