Wear behaviour of metals in dry sliding against molybdenum with current collection

2020 ◽  
pp. 118-125
Author(s):  
M. I. Aleutdinova ◽  
V. V. Fadin
Keyword(s):  
Electrical Conductivity ◽  
Electrical Contact ◽  
Wear Behaviour ◽  
High Wear Resistance ◽  
Dry Sliding ◽  
High Electrical Conductivity ◽  
Current Collection ◽  
Ferrous Metals ◽  
Non Ferrous Metals ◽  
Sliding Electrical Contact

The possibility of high electrical conductivity of dry sliding electrical contact against molybdenum counterbody was studied. It was found that metals W and Cu were not able to form a sliding electrical contact with high wear resistance at current density higher 100 A/cm2 . The characteristics of the contacts of iron containing metals were slightly better than the contact characteristics of non-ferrous metals due to weaker adhesion. Using X-ray phase analysis, it was shown the absence of oxides in the sliding zone of non-ferrous metals. This led to their strong wear and contact’s low electrical conductivity. In the contact zone of iron containing samples the formation of FeO was observed that made it possible to reduce wear. This means that high electrical conductivity is unattainable in sliding with current collection against molybdenum.

Dependance of Wear of Cu-Cr-S Alloy on Hardness and Electrical Conductivity in Sliding Electrical Contact

2017 ◽  
Vol 267 ◽  
pp. 229-233
Author(s):  
Lembit Kommel ◽  
Janis Baroninš
Keyword(s):  
Heat Treatment ◽  
Electrical Conductivity ◽  
Vickers Microhardness ◽  
Electrical Contact ◽  
High Electrical Conductivity ◽  
High Tensile Strength ◽  
Equal Channel Angular Press ◽  
Suitable Heat Treatment ◽  
Sliding Electrical Contact ◽  
Wear Tests

Wear of material in unlubricated sliding type electrical contact (e.g. contact wires for trolleys and rotor materials in electric engines and current generators) is one of the main failure causing modes of copper (Cu)-based alloys. High electrical conductivity, high tensile strength, suitable hardness and wear resistance under such conditions should be provided. In a present paper required properties of dispersion-hardened Cu-based electrical conductive alloy (Cu-0.68 wt. % Cr-0.02 wt. % S) were obtained by equal-channel angular press treatment with following six press treatments by Bc route and suitable heat treatment. The wear tests were carried out in unlubricated sliding pair with graphite disk. Optimal properties were reached after annealing at 450 °C for 1 h, exhibiting a lowest wear rate (~1.9268·10-9 g·m-1), high electrical conductivity (up to 95 % IACS) and Vickers microhardness up to 1.7 GPa, respectively.

Interaction of tungsten in dry sliding against steel under high density electric current

2019 ◽  
pp. 101-109 ◽  
Author(s):  
M. I. Aleutdinova ◽  
V. V. Fadin ◽  
Yu. P. Mironov
Keyword(s):  
Electrical Contact ◽  
Analysis Data ◽  
Dry Sliding ◽  
Sliding Surface ◽  
X Ray ◽  
Sliding Surfaces ◽  
Quenched Steel ◽  
Sliding Electrical Contact ◽  
A Current ◽  
Tungsten Steel

The possibility of creating a wear-resistant dry sliding electrical contact tungsten/steel was studied. It was shown that tungsten caused severe wear of the quenched steel counterbody due to unlimited plastic flow of its surface layer at a current density up to 150 A/cm2 . This indicated the impossibility of achieving satisfactory characteristics of such a contact. Low electrical conductivity and wear resistance of the contact tungsten/steel were presented in comparison with the known high copper/steel contact characteristics under the same conditions. X-ray phase analysis data of the steel sliding surfaces made it possible to state that the cause of the unsatisfactory sliding of tungsten was the absence of the necessary concentration of FeO oxide on the sliding surface of the steel. 

Dry Sliding Wear Behaviour of Fe-Based Powder Sintered Steel

2011 ◽  
Vol 415-417 ◽  
pp. 707-710
Author(s):  
Hua Chen ◽  
Hai Ying Sun
Keyword(s):  
Wear Resistance ◽  
Wear Mechanism ◽  
Sliding Wear ◽  
Hot Forging ◽  
Wear Behaviour ◽  
High Wear Resistance ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Delamination Wear ◽  
Sliding Wear Behaviour

Fe-based system powder metallurgy in the as-sintered was investigated on pin-on-rolling wear tester for their dry sliding wear behaviour. The morphology of worn surfaces and wear mechanism were analysed by SEM. Results show the hot-forging deformation quenching and tempered considerably decreased the porosity and improved wear resistance, and compare with quenching microstructure, tempered microstructure has high wear resistance and match of strength-toughness. Fe-2.0Ni-0.4Mo-0.5C-0.6Cr alloy presented best wear characteristics. SEM observations of the worn surface revealed microploughing and plastic deformation and crack were the basic dry sliding wear morphology,and oxidative wear and delamination wear are dominant wear mechanism.

scholarly journals Deterioration of surface layers of tungsten and steel-containing materials in current collection sliding against molybdenum

2021 ◽  
Vol 64 (2) ◽  
pp. 122-128
Author(s):  
M. I. Aleutdinova ◽  
V. V. Fadin
Keyword(s):  
Electrical Conductivity ◽  
Iron Oxides ◽  
Electrical Contact ◽  
Bearing Steel ◽  
Wear Intensity ◽  
Oxide Content ◽  
Molybdenum Oxides ◽  
Sliding Surface ◽  
Surface Layers ◽  
Current Collection

The possibility of improving the characteristics of a dry sliding electrical contact with a current density higher than 100 A/cm2 by using a molybdenum counterbody is considered. It is shown that tungsten or metallic materials containing bearing steel (1.5 % Cr) in sliding against molybdenum at a speed of 5 m/s under electric current, forms a contact with low electrical conductivity and high wear intensity. This observation served as the basis of this work. Using optical and electron microscopy of sliding surfaces it was found that strong adhesion in the interface was the main reason for rapid surface layers deterioration and high wear intensity. A well-known statement was taken into account that adhesion is due to the low oxide content between the contact surfaces. Visual study of molybdenum sliding surface made it possible to establish formation of a thin transfer layer and absence of traces of oxide formation. The same was observed on sliding surface of tungsten that was caused by high temperature of tungsten and molybdenum oxides formation. A layer of iron oxides was observed on sliding surface of steel containing materials. In addition, traces of a thin tribolayer were find out. An increase in concentration of steel in the primary structure led to a slight increase in iron oxides on the sliding surface, but did not lead to a significant increase in electrical conductivity and wear resistance of the contact. Unsatisfactory characteristics of the contact allowed us to conclude that it is impossible to significantly improve sliding parameters with current collection against molybdenum and inappropriateness of its use as a counterbody for these conditions.

scholarly journals Correlation between Wear Resistance and Lifetime of Electrical Contacts

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Jian Song ◽  
Christian Koch ◽  
Liangliang Wang
Keyword(s):  
Electrical Conductivity ◽  
Wear Resistance ◽  
High Performance ◽  
Electrical Contacts ◽  
Electrical Performance ◽  
High Wear Resistance ◽  
High Electrical Conductivity ◽  
Fretting Corrosion ◽  
Long Lifetime

Electrical contacts are usually plated in order to prevent corrosion. Platings of detachable electrical contacts experience wear because of the motion between contacts. Once the protecting platings have been worn out, electrical contacts will fail rapidly due to corrosion or fretting corrosion. Therefore the wear resistance of the platings is a very important parameter for the long lifetime of electrical contacts. Many measures which improve the wear resistance can diminish the conductivity of the platings. Due to the fact that platings of electrical contacts must have both a high wear resistance and a high electrical conductivity, the manufacturing of high performance platings of electrical contacts poses a great challenge. Our study shows firstly the correlation between the wear resistance of platings and lifetime of electrical contacts and then the measures, which improve the wear resistance without impairing the electrical performance of the contacts.

scholarly journals Electromagnetic measurement of level and conductivity of non-ferrous metals

2020 ◽  
pp. 63-68
Author(s):  
G. L. Losev ◽  
◽  
V. A. Eltishchev ◽  
Keyword(s):  
Electrical Conductivity ◽  
Alkali Metals ◽  
Measurement Accuracy ◽  
Non Invasive ◽  
Ferrous Metals ◽  
Non Ferrous Metals ◽  
Electromagnetic Measurement

The paper presents the developed electromagnetic non-invasive level and electrical conductivity sensors for non-ferrous and alkali metals. The influence of the geometry of the installations on the measurement accuracy was experimentally determined. The limits of permissible errors in the positioning of the sensors relative to the analyzed volumes of metals are established.

Effects of tool pin profile on tensile and wear behaviour of friction stir welded AA6101-T6 and AA1350 alloys

2020 ◽  
Vol 117 (5) ◽  
pp. 503
Author(s):  
R. Ashok kumar ◽  
R. Muneeswaran ◽  
M. Saravana Mohan ◽  
Sathish Rengarajan ◽  
G.R. Raghav ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Friction Stir Welding ◽  
Solid State ◽  
Frictional Heat ◽  
Wear Behaviour ◽  
Base Metals ◽  
High Electrical Conductivity ◽  
Wear Properties ◽  
Friction Stir ◽  
Tool Pin

In Friction Stir Welding (FSW) technique, hard rotating tool with specially profiled pin is plunged into base metals and traversed along the interface of the plates, generating the frictional heat and plasticizing the base metals. This leads to flow of materials and makes solid state joint. AA6101-T6 and AA1350 alloys are widely applied in electrical bus bars, because of their high electrical conductivity. In this present work, these two alloys are joined by varying the pin profile of the tools as circular, triangular, square and hexagonal. Of these four joints, the joint fabricated by circular pin profiled tool exhibits poor tensile and wear properties whereas hexagonal pin profiled tool exhibits better tensile and wear properties. This is due to the volume defects and grain refinement at stirred zone.

Study of Microstructure and Wear Behavior of T6 Heat Treated as Cast Al-25Mg2Si-2Cu Alloy

2015 ◽  
Vol 830-831 ◽  
pp. 358-361 ◽  
Author(s):  
D.G. Sondur ◽  
D.M. Goudar ◽  
D.G. Mallapur ◽  
G.B. Rudrakshi
Keyword(s):  
Wear Resistance ◽  
Sliding Wear ◽  
Wear Behavior ◽  
Cast Alloy ◽  
Wear Test ◽  
Wear Behaviour ◽  
High Wear Resistance ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Heat Treated

In the present investigation, microstructural characteristics and dry sliding wear behaviour of T6 heat treated conventionally cast Al-25Mg2Si-2Cu alloy have been discussed. The as cast alloy was subjected to solutionizing at 500°C for 5h and isothermal aging treatment at 190°C for different aging times. The micro structural characterization was studied using Scanning Electron Microscope with EDS analysis. The microstructure of as cast alloy consists of intermetallics of coarse block like sharp edged β-(Mg2Si), θ-(Al2Cu) and Q-(Al-Mg-Cu-Si) in the form of Chinese scripts and needles distributed randomly in the Al-matrix. The microstructure of heat treated alloy shows spheroidization of β phase and fine precipitation of θ-(Al2Cu) and Q phases. The dry sliding wear test was carried out using pin-on-disc machine. Age hardened alloy exhibits high wear resistance and minimum coefficient of friction over the entire range of applied loads and sliding velocities. Furthermore, high wear resistance was observed in the under aged condition compared to over ageing conditions.

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