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.

Characteristic properties of AlTiN and TiN coated HSS materials

2015 ◽  
Vol 67 (2) ◽  
pp. 172-180 ◽  
Author(s):  
Mumin Sahin ◽  
Cenk Misirli ◽  
Dervis Özkan
Keyword(s):  
Surface Roughness ◽  
Tensile Strength ◽  
High Speed ◽  
Cutting Tools ◽  
High Speed Steel ◽  
Wear Properties ◽  
Content Type ◽  
X Ray ◽  
Number Of Cycles ◽  
Future Work

Purpose – The purpose of this paper is to examine mechanical and metallurgical properties of AlTiN- and TiN-coates high-speed steel (HSS) materials in detail. Design/methodology/approach – In this study, HSS steel parts have been processed through machining and have been coated with AlTiN and TiN on physical vapour deposition workbench at approximately 6,500°C for 4 hours. Tensile strength, fatigue strength, hardness tests for AlTiN- and TiN-coated HSS samples have been performed; moreover, energy dispersive X-ray spectroscopy and X-ray diffraction analysis and microstructure analysis have been made by scanning electron microscopy. The obtained results have been compared with uncoated HSS components. Findings – It was found that tensile strength of TiAlN- and TiN-coated HSS parts is higher than that of uncoated HSS parts. Highest tensile strength has been obtained from TiN-coated HSS parts. Number of cycles for failure of TiAlN- and TiN-coated HSS parts is higher than that for HSS parts. Particularly TiN-coated HSS parts have the most valuable fatigue results. However, surface roughness of fatigue samples may cause notch effect. For this reason, surface roughness of coated HSS parts is compared with that of uncoated ones. While the average surface roughness (Ra) of the uncoated samples was in the range of 0.40 μm, that of the AlTiN- and TiN-coated samples was in the range of 0.60 and 0.80 μm, respectively. Research limitations/implications – It would be interesting to search different coatings for cutting tools. It could be the good idea for future work to concentrate on wear properties of tool materials. Practical implications – The detailed mechanical and metallurgical results can be used to assess the AlTiN and TiN coating applications in HSS materials. Originality/value – This paper provides information on mechanical and metallurgical behaviour of AlTiN- and TiN-coated HSS materials and offers practical help for researchers and scientists working in the coating area.

Tribological behavior of AZ91D magnesium alloy composite: effect of hybrid WC – SiO2 nanoparticles

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohammed Fahad ◽  
Bavanish B.
Keyword(s):  
Magnesium Alloy ◽  
Wear Rate ◽  
Az91d Alloy ◽  
Hybrid Particles ◽  
Wear Properties ◽  
Sliding Speed ◽  
Composite Effect ◽  
Content Type ◽  
Climate Conditions ◽  
Az91d Magnesium Alloy

Purpose Aviation field requires a material with greater tribological characteristics to withstand the critical climate conditions. Hence, it is of paramount importance to enhance the wear resistance of material. AZ91D magnesium alloy is a light weight material used in the aviation field for the construction work. The purpose of this study is to augment the wear properties of AZ91D alloy by reinforcing with hard particles such as tungsten carbide (WC) and silicon dioxide (SiO2). Design/methodology/approach In this work, three types of composites were fabricated, namely, AZ91D – WC, AZ91D – SiO2 and AZ91D – (WC + SiO2) by ball milling method, and the tribological properties were analyzed using pin-on-disc apparatus. Findings Results showed that the hardness of AZ91D alloy was greatly improved due to the reinforcing effects of WC and SiO2 particles. Wear study showed that wear rate of AZ91D alloy and its composites increased with the increase of applied load due to ploughing effect and decreased with the increase of sliding speed owing to the formation of lubricating tribolayer. Further, the AZ91D – (WC + SiO2) composite exhibited the lower wear rate of 0.0017 mm3/m and minimum coefficient of friction of 0.33 at a load of 10 N and a sliding speed of 150 mm/s due to the inclusion of hybrid WC and SiO2 particles. Hence, the proposed AZ91D – (WC + SiO2) composite could be a suitable candidate to be used in the aviation applications. Originality/value This work is original which deals with the effect of hybrid particles, i.e. WC and SiO2 on the wear performance of the AZ91D magnesium alloy composites. The literature review showed that none of the studies focused on the reinforcement of AZ91D alloy by the combination of carbide and metal oxide particles as used in this investigation.

Wear Properties of Metal-Impregnated Carbon Fiber-Reinforced Carbon Composite Sliding Against a Copper Plate Under an Electric Current

2005 ◽  
Author(s):  
Shunichi Kubo ◽  
Hiroshi Tsuchiya
Keyword(s):  
Carbon Fiber ◽  
Electric Current ◽  
High Speed ◽  
Carbon Composite ◽  
Copper Plate ◽  
Fiber Reinforced ◽  
Wear Properties ◽  
Copper Disk ◽  
Carbon Fiber Reinforced ◽  
Arc Discharges

The metal-impregnated carbon fiber-reinforced carbon composite (C/C composite) is expected to be a candidate material for pantograph contact strips of high-speed electric railway vehicles, because its mechanical strength for flexure and impact is much higher than that of the conventional metal-impregnated carbon. The authors have investigated the wear properties of copper-titanium-alloy impregnated C/C composite sliding against a copper disk under an electric current and frequent arc discharges. The tested C/C composite was prepared by press molding and baking of laminated carbon fiber woven sheets. There exists anisotropy in the physical properties originated from the orientation of carbon fiber woven sheets lamination. The C/C composite was slid in two directions, in parallel with or perpendicular to the sheet layer. The test results show that the wear rate in sliding in the parallel direction exceeds that in the perpendicular direction, especially in the cases where the material is subjected to higher current density and more frequent arc discharges.

scholarly journals High-speed data provision via mobile networks in Latin America and the Caribbean

2017 ◽  
Vol 19 (4) ◽  
pp. 287-301 ◽  
Author(s):  
Peter Curwen ◽  
Jason Whalley
Keyword(s):  
Latin American ◽  
Mobile Networks ◽  
High Speed ◽  
Individual Country ◽  
Content Type ◽  
Caribbean Islands ◽  
Data Provision ◽  
High Speed Data ◽  
The Media ◽  
New Entry

Purpose The purpose of this paper is to examine in a fully up-to-date manner the position in respect of the licensing and launch of long-term evolution (LTE) (4G) in a region that attracts relatively little attention in academic work and the media. The purpose is also to examine the role of incumbency and to assess to what extent the licensing of LTE can make a difference to the structure of mobile markets in the region. Design/methodology/approach The first step has been to compile extensive databases with respect to the licensing and launch of high-speed networks in the region, arranged so as to emphasize the position of the dominant incumbents. A distinction is drawn between the larger, mainly Latin American, countries and the smaller, mainly Caribbean, islands. There is a discussion of new entry and its potential to disrupt incumbents. Findings The position of dominance held by two operators – América Móvil and Telefonica in the larger countries and by Digicel and Cable & Wireless Communications (Liberty Global) in the islands – is brought to the fore, and the analysis demonstrates that this is unlikely to be more than marginally affected by regulatory attempts to restructure markets by, for example, fostering new entry. Research limitations/implications This is necessarily an overview paper as more than 50 countries/islands are covered, so detailed individual country studies are precluded. Practical implications The way forward, such as it is, can only be illuminated by first clarifying the current state of play. Originality/value The databases that underpin the analysis are author-compiled and entirely original.

scholarly journals Study on Friction and Wear Properties of Pantograph Strip/Copper Contact Wire for High-Speed Train

2014 ◽  
Vol 8 (1) ◽  
pp. 125-128 ◽  
Author(s):  
Tao Ding ◽  
Wenjing Xuan ◽  
Qiudong He ◽  
Hao Wu ◽  
Wei Xiong
Keyword(s):  
Wear Rate ◽  
Electric Current ◽  
High Speed ◽  
Friction And Wear ◽  
Optical Microscope ◽  
Wear Properties ◽  
Contact Wire ◽  
Arc Erosion ◽  
The Coefficient Of Friction ◽  
Friction And Wear Properties

A series of experiments on friction and wear properties of carbon strip rubbing against copper contact wire is performed on high-speed friction and wear tester with electric current. The results show that the friction coefficient is generally maintained between 0.24 and 0.37. In the absence of electric current, the coefficient of friction is higher than that in the presence of electric current. The wear rate of carbon strip materials is generally not more than 0.014g/km. In particular, the wear rate under the electric current of 240 A is 14 times more than that in the absence of electric current. By observing the scar of worn surface with optical microscope, it can be found that there are obvious slip scars and arc erosive pits. The dominated wear mechanisms are abrasive wear and arc erosion in electrical sliding frictional process.

A novel design of nano router with high-speed crossbar scheduler for digital systems in QCA paradigm

Circuit World ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kalpana Kasilingam ◽  
Paulchamy Balaiah
Keyword(s):  
High Speed ◽  
Complementary Metal Oxide Semiconductor ◽  
Cmos Technology ◽  
Modern Technology ◽  
Oxide Semiconductor ◽  
Large Area ◽  
Content Type ◽  
Compact Size ◽  
High Power Consumption ◽  
High Speed Data

Purpose The nano-router would be a mastery device for providing high-speed data delivery. Here nano-router with a space-efficient crossbar scheduler is used for making absolutely less consumption in power. Design/methodology/approach In the emerging modern technology, every one of us is expecting a delivery of data at a high speed. To achieve high-speed delivery the authors are using the router. The router used here is at nanoscale reading which provides a compact size. Findings This can be implemented using the modern tools called Quantum-dot Cellular Automata (QCA) which is operated without the use of a transistor. As conventional complementary metal oxide semiconductor (CMOS) designs have some limitations such as low density, high power consumption and requirement of a large area. Research limitations/implications To overcome these limitations the QCA is used. It characterizes capability is used to substituting CMOS technology. The round-robin fashion is used in a high-speed space-efficient crossbar scheduler. Practical implications The simulation of the planned circuit with notional information established the practical identity of the scheme. Social implications The proposed nano router can be stimulated in the QCA environment using the QCADesigner tool and the power of the router can be calculated with the QCADesigner–E tool. Originality/value The proposed nano router can be stimulated in the QCA environment using the QCADesigner tool and the power of the router can be calculated with the QCADesigner–E tool. In this work, the performance of the router can be done in both the QCA environment and CMOS technology.

The influence of risks on the outturn cost of ICT infrastructure network projects

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Khalid Almarri ◽  
Halim Boussabaine ◽  
Hamad Al Nauimi
Keyword(s):  
High Speed ◽  
Data Networks ◽  
Content Type ◽  
Infrastructure Network ◽  
Information And Communication ◽  
Project Risks ◽  
High Speed Data ◽  
Ict Infrastructure ◽  
The Relationship ◽  
Network Project

Purpose The internet of things (IoT) is becoming an increasingly inescapable part of society. IoT paradigm cannot function without the networking infrastructure. High-speed data networks are essential to enable the IoT future. Thus, the purpose of this study is on the identification of risks that influence the development, installation and operation of information and communication technology (ICT) infrastructure network project cost outcomes. So far, there has been little attention has been paid to risks problems in these types of IoT enabling projects. Design/methodology/approach This research follows a quantitative analysis approach. Data for this study were collected by a survey from 209 professionals. Multiple regression analysis was used to model the relationship between risks and outturn cost of infrastructure needed to enable the operation of IoT technologies. Findings The main risk factors that were identified were planning and development, people and management, operations, technology and hardware. Research limitations/implications This research has expanded the existing literature by documenting and clustering ICT infrastructure network project risks into themes, and has developed a scale (risk statements) for measuring such risks. Further, the research has advanced the understanding by identifying the most likely risks that will contribute to the overrun of these projects. Originality/value This research establishes a reliable regression method for the assessment of the risks that influence the development, installation and operation of ICT infrastructure network projects outturn cost. No other research has measured or studied the risks in this type of project.

scholarly journals Wear Behaviors of Three Typical Bulk Metallic Glasses in Bearing Applications

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1005 ◽  
Author(s):  
Dong-Hui Wang ◽  
Sheng-Hui Xie ◽  
Hai-Peng Yang ◽  
Hai-Xia Qian ◽  
Xie-Rong Zeng
Keyword(s):  
Wear Behavior ◽  
Normal Load ◽  
Friction Pair ◽  
High Strength ◽  
Wear Loss ◽  
Wear Properties ◽  
Sliding Speed ◽  
Lithium Grease ◽  
Gcr15 Steel ◽  
Bearing Materials

In bearing applications, the development of new materials has become a focus of scientific research in order to make bearing systems smaller and rotate more accurately. Bulk metallic glass (BMG), which has high strength, stiffness and resistance to corrosion, is becoming a promising candidate for bearing and shaft materials. When used as shafts, the friction feature of BMG needs to be evaluated comprehensively. In this work, the friction and wear properties of Ni-based, Zr-based, and Cu-based BMGs sliding against brass lubricated with lithium grease were investigated, using traditional bearing materials (GCr15 steel) as comparison. The results showed that the wear mechanism of the BMGs was primarily abrasive, supplemented by an adhesive wear behavior when sliding against brass plates, just like GCr15 steel. The wear loss of the friction pair (brass plates) increases when the applied normal load increases and the sliding speed decreases. Compared with GCr15 steel, BMGs exhibit better friction performance at low sliding speed, and Ni-based BMG always exhibits a smaller wear loss, especially under large load and low sliding speed. The wear loss of brass plates against Ni-based BMG pin is 24.3% lower than that against GCr15 steel under an applied load of 10 kg, which indicates that Ni-based BMG is an attractive bearing and shaft material for industrial application.

Fabrication and tribological study of AA6061 hybrid metal matrix composites reinforced with SiC/B4C nanoparticles

2019 ◽  
Vol 71 (1) ◽  
pp. 83-93 ◽  
Author(s):  
Shubhajit Das ◽  
Chandrasekaran M. ◽  
Sutanu Samanta ◽  
Palanikumar Kayaroganam ◽  
Paulo Davim J.
Keyword(s):  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Hybrid Composites ◽  
Normal Load ◽  
Matrix Composites ◽  
Sliding Speed ◽  
Ceramic Particles ◽  
Content Type ◽  
Ceramic Nanoparticles ◽  
Hybrid Metal Matrix Composites

Purpose Composite materials are replacing the traditional materials because of their remarkable properties and the addition of nanoparticles making a new trend in material world. The nano addition effect on tribological properties is essential to be used in automotive and industrial applications. The current work investigates the sliding wear behavior of an aluminum alloy (AA) 6061-based hybrid metal matrix composites (HMMCs) reinforced with SiC and B4C ceramic nanoparticles. Design/methodology/approach The hybrid composites are fabricated using stir casting process. Two different compositions were fabricated by varying the weight percentage of the ceramic reinforcements. An attempt has been made to study the wear and friction behavior of the composites using pin-on-disc tribometer to consider the effects of sliding speed, sliding distance and the normal load applied. Findings The tribological tests are carried out and the performances were compared. Increase in sliding speed to 500 rpm resulted in the rise of temperature of the contacting tribo-surface which intensified the wear rate at 30N load for the HMMC. The presence of the ceramic particles further reduced the contact region of the mating surface thus reducing the coefficient of friction at higher sliding speeds. Oxidation, adhesion, and abrasion were identified to be the main wear mechanisms which were further confirmed using energy dispersive spectroscopy and field emission scanning electron microscopy (FESEM) of the worn out samples. Practical implications The enhancement of wear properties is achieved because of the addition of the SiC and B4C ceramic nanoparticles, in which these composites can be applied to automobile, aerospace and industrial products where the mating parts with less weight is required. Originality/value The influence of nanoparticles on the tribological performance is studied in detail comprising of two different ceramic particles which is almost new research. The sliding effect of hybrid composites with nano materials paves the way for using these materials in engineering and domestic applications.

Investigation of Friction and Wear Properties of Electroless Ni–P–Cu Coating Under Dry Condition

2016 ◽  
Vol 04 (04) ◽  
pp. 1640013 ◽  
Author(s):  
Santanu Duari ◽  
Arkadeb Mukhopadhyay ◽  
Tapan Kr. Barman ◽  
Prasanta Sahoo
Keyword(s):  
Heat Treatment ◽  
Surface Morphology ◽  
Normal Load ◽  
Wear Depth ◽  
Wear Properties ◽  
Sliding Speed ◽  
Applied Normal Load ◽  
Heat Treated ◽  
Pin On Disc ◽  
Electroless Ni

This study presents the deposition and tribological characterization of electroless Ni–P–Cu coatings deposited on AISI 1040 steel specimens. After deposition, coatings are heat treated at 500[Formula: see text]C for 1[Formula: see text]h. Surface morphology study of the coatings reveals its typical cauliflower like appearance. Composition study of the coatings using energy dispersive X-ray analysis indicates that the deposit lies in the high phosphorus range. The coatings undergo crystallization on heat treatment. A significant improvement in microhardness of the coatings is also observed on heat treatment due to the precipitation of hard crystalline phases. The heat-treated coatings are subjected to sliding wear tests on a pin-on-disc type tribo-tester under dry condition by varying the applied normal load, sliding speed and sliding duration. The coefficient of friction (COF) increases with an increase in the applied normal load while it decreases with an increase in the sliding speed. The wear depth on the other hand increases with an increase in applied normal load as well as sliding speed. The worn surface morphology mainly indicates fracture of the nodules.

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