THE TRIBOLOGICAL CHARACTERISTICS OF Al-Si/GRAPHITE COMPOSITE

Tribologia ◽  
2018 ◽  
Vol 271 (1) ◽  
pp. 97-104
Author(s):  
Mariusz WALCZAK ◽  
Maciej ZWIERZCHOWSKI ◽  
Jarosław BIENIAŚ ◽  
Jacek CABAN
Keyword(s):  
Automotive Industry ◽  
Construction Material ◽  
High Tech ◽  
Aluminium Composite ◽  
Graphite Composite ◽  
Graphite Particles ◽  
The Matrix ◽  
Cylinder Liners ◽  
Wear Tests ◽  
Ball On Disc

The paper presents the results of tribological research on AlSi12CuNiMg/5.7 wt.% Gr aluminium composite material (containing graphite particles in the amount of 5.7% wt.%) and on its matrix. This composite is used as high-tech construction material in the automotive industry, particularly for pistons, cylinder liners, and slide bearings. The tribological properties of these materials can be significantly changed as a result of the introduction of graphite particles. Therefore, wear tests have been carried out using the ball-on-disc tribometer. Microstructure and wear resistance of the matrix and composite alloy have been subjected to comparative analysis. It was demonstrated that the composite reinforced with graphite is characterized by a lower friction coefficient and lower wear in comparison to the matrix.

An overview of biopolymer-based nanocomposites for optics and electronics

2021 ◽  
Author(s):  
Elena Colusso ◽  
Alessandro Martucci
Keyword(s):  
High Tech ◽  
New Materials ◽  
Recent Advances ◽  
The Matrix

We summarize the recent advances in optics and electronics of biopolymer-based nanocomposites. They are emerging as new materials for high-tech applications, thanks to the sustainability of the matrix and the functionalities of the nanofillers.

INTERCONNECTION BETWEEN GLOBAL SUPPLY CHAINS AND INDUSTRY

2021 ◽  
pp. 6-11
Author(s):  
Alexander N. Bryntsev ◽  
◽  
M.A. Bykova ◽  
Keyword(s):  
Artificial Intelligence ◽  
Supply Chains ◽  
Automotive Industry ◽  
Industrial Production ◽  
High Tech ◽  
Global Supply Chains ◽  
Global Competition ◽  
Macroeconomic Analysis ◽  
The Relationship

In the article, the authors consider the issues of the relationship between global supply chains and industrial production of semiconductors in modern conditions. Particular attention is paid to the applied value of the application of artificial intelligence technologies in industry in the light of the growth of global competition. Their specific features, strengths and weaknesses are shown. A brief macroeconomic analysis of the development of markets for robotics, the automotive industry, high-tech products, as well as modern regulations on the eve of a new technological order is given.

An Application of Fuzzy Clustering to Customer Portfolio Analysis in Automotive Industry

2016 ◽  
Vol 5 (2) ◽  
pp. 13-25
Author(s):  
Abdulkadir Hiziroglu ◽  
Umit Dursun Senbas
Keyword(s):  
Fuzzy Clustering ◽  
Automotive Industry ◽  
Quantitative Assessment ◽  
Portfolio Analysis ◽  
Matrix Form ◽  
Automotive Supplier ◽  
Qualitative And Quantitative ◽  
Marketing Managers ◽  
The Matrix

Having achieved an optimized customer portfolio has been of significant importance for companies. The literature provides several portfolio models and vast majority of them are in matrix form where several descriptors are used as dimensions of the matrix. These dimensions are characterized in ambiguity and require specific methods to tackle with it. The aim of this paper is to utilize fuzzy clustering in customer portfolio analysis to reduce this uncertainty and to make a comparison with a traditional customer portfolio model. A dataset of 130 customers of an automotive supplier in Turkey is used to perform the analyses and the results are compared with a conventional customer portfolio matrix. By making use of substantiality and balance of portfolio parameters, a qualitative and quantitative assessment of categorization generated by both approaches are evaluated. The use of fuzzy clustering gives more substantial clusters and a more balanced customer portfolio compared to the traditional matrix form of portfolio. Marketing managers can understand their overall customer portfolio better and reduce the effect of descriptive indicators via benefiting the fuzzy clustering results.

scholarly journals The Influence of Disc Surface Topography after Vapor Blasting on Wear of Sliding Pairs under Dry Sliding Conditions

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 102 ◽  
Author(s):  
Dzierwa ◽  
Pawlus ◽  
Zelasko
Keyword(s):  
Surface Topography ◽  
Tribological Properties ◽  
White Light ◽  
Dry Friction ◽  
Dry Sliding ◽  
Disc Surface ◽  
Steel Disc ◽  
42Crmo4 Steel ◽  
Wear Tests ◽  
Ball On Disc

Wear tests were performed using a ball-on-disc tribological tester. In this study, 42CrMo4 steel disc of hardness 40 HRC co-acted with 100Cr6 steel ball with hardness of 60 HRC. Disc surfaces were created using vapor blasting to obtain values of the Sq parameter close to 5 µm. However, other disc surface topography parameters varied. Dry friction tests were carried out. Wear levels of discs and balls were measured using a white light interferometer Talysurf CCI Lite. It was found that the surface topography had a significant impact on tribological properties under dry sliding conditions. The research also allowed to identify significant dependencies between surface topography parameters and wear.

scholarly journals 9,10-ANTHRAQUINONE-2,6-DISULFONIC ACID DISODIUM SALT/ EPOXY GRAPHITE COMPOSITE FOR ANODE IN MICROBIAL FUEL CELL

2017 ◽  
Vol 79 (5-3) ◽  
Author(s):  
Mimi Hani Abu Bakar ◽  
Neil F Pasco ◽  
Ravi Gooneratne ◽  
Kim Byung Hong
Keyword(s):  
Fuel Cell ◽  
Microbial Fuel Cell ◽  
Conductive Filler ◽  
Internal Resistance ◽  
Disodium Salt ◽  
Disulfonic Acid ◽  
Graphite Composite ◽  
Design Flexibility ◽  
Matrix Surface ◽  
The Matrix

Properties such as electrical conductivity, low resistivity, chemicals and corrosion resistance are mostly found in carbon based materials. Epoxy resin is excellent for electrical insulation and can be used as a conductor with the addition of conductive filler. Combinations of carbon and epoxy show qualities of a conductive electrode, mechanically strong with design flexibility and thus makes them suitable as electrodes in microbial fuel cell (MFC). In this study, graphite-epoxy composites were fabricated with multi-walled carbon nanotube (MWCNT) embedded in the matrix surface. 9,10-Anthraquinone-2,6-disulfonic acid disodium salt/polypyrrole (PPy/AQDS) was used as mediator, covalently electrografted on electrode’s surface. Electrochemical stability of anodes during continuous operation were measured in air-cathode MFCs. It appears that maximum power in MFC could be increased up to 42% with surface modification using PPy/AQDS. Internal resistance (Rint) could be reduced up to 66% with the inclusion of MWCNT. These findings show that a one-day fabrication of a-ready-to-use conductive electrode is possible for graphite content between 70-80% (w/w).

scholarly journals The Effect of Thickness on the Properties of Laser-Deposited NiBSi-WC Coating on a Cu-Cr-Zr Substrate

Photonics ◽  
2019 ◽  
Vol 6 (4) ◽  
pp. 127
Author(s):  
Yury Korobov ◽  
Yulia Khudorozhkova ◽  
Holger Hillig ◽  
Alexander Vopneruk ◽  
Aleksandr Kotelnikov ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Matrix Material ◽  
Copper Substrate ◽  
Thin Layers ◽  
Laser Deposition ◽  
The Matrix ◽  
High Level ◽  
Primary Carbides ◽  
Matrix Powder ◽  
Wear Tests

Ni/60WC coatings on copper substrate were placed via laser deposition (LD). A structural study was conducted using electron microscopy and a microhardness evaluation. Two body abrasive wear tests were conducted with a pin-on-plate reciprocating technique. A tool steel X12MF GOST 5960 (C-Cr-Mo-V 1.6-12-0.5-0.2) with a hardness of 63 HRC was used as a counterpart. The following results were obtained: Precipitation of the secondary carbides takes place in the thicker layers. Their hardness is lower than that of the primary carbides in the deposition (2425 HV vs. 2757 HV) because they mix with the matrix material. In the thin layers, precipitation is restricted due to a higher cooling rate. For both LD coatings, the carbide’s hardness increases compared to the initial mono-tungsten carbide (WC)-containing powder (2756 HV vs. 2200 HV). Such a high level of microhardness reflects the combined influence of a low level of thermal destruction of carbides during laser deposition and the formation of a boride-strengthening phase from the matrix powder. The thicker layer showed a higher wear resistance; weight loss was 20% lower. The changes in the thickness of the laser deposited Ni-WC coating altered its structure and wear resistance.

Pressure Influence on the AlCrFeNiMn/Graphite High Entropy Composite Microhardness

2017 ◽  
Vol 750 ◽  
pp. 9-14
Author(s):  
Gabriela Popescu ◽  
Mihai Branzei ◽  
Cristian Aurelian Popescu ◽  
Alecs Andrei Matei ◽  
Roxana Trusca ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
High Entropy Alloys ◽  
X Rays ◽  
High Entropy ◽  
Graphite Particles ◽  
The Matrix ◽  
Microhardness And Microstructure ◽  
Near Net Shape ◽  
Chemical Distribution ◽  
Scanning Electron

During the last years, mechanical alloying technique for high entropy alloys (HEAs) has been more often approached due to the good homogenous chemical distribution and near net shape technology provided by the respectively process. A new composite material having the matrix as HEA reinforced with graphite particles was designed. The graphite particles addition in the high entropy matrix (AlCrFeNiMn) improves the particles weldability during mechanical alloying and assures a good creep behavior for the final product. The aim of this paper is to investigate the pressure influence on the microhardness as dependence of sintering parameters which can be reflected also on the microstructure. The high entropy composite was completely alloyed after 40 hours of milling. The obtained composite was pressed using different pressures values in order to investigate the pressure influence on the microhardness and microstructure. The samples were investigated using optical microscopy, scanning electron microscopy, X-rays diffraction and microhardness tests. The microhardness values for all the samples were between 300 – 700 HV.

scholarly journals Effect of Increasing the Strength of Aluminum Matrix Nanocomposites Reinforced with Microadditions of Multiwalled Carbon Nanotubes Coated with TiC Nanoparticles

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1596 ◽  
Author(s):  
Artemiy Aborkin ◽  
Kirill Khorkov ◽  
Evgeny Prusov ◽  
Anatoly Ob’edkov ◽  
Kirill Kremlev ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Aluminum Matrix ◽  
High Energy ◽  
High Tech ◽  
Multiwalled Carbon ◽  
The Matrix ◽  
Tic Nanoparticles ◽  
Matrix Nanocomposites

Aluminum matrix composites reinforced with multiwalled carbon nanotubes (MWCNTs) are promising materials for applications in various high-tech industries. Control over the processes of interfacial interaction in Al/MWCNT composites is important to achieve a high level of mechanical properties. The present study describes the effects of coating MWCNTs with titanium carbide nanoparticles on the formation of mechanical properties and the evolution of the reinforcement structure in bulk aluminum matrix nanocomposites with low concentrations of MWCNTs under conditions of solid-phase consolidation of ball-milled powder mixtures. Using high-energy ball milling and uniaxial hot pressing, two types of bulk nanocomposites based on aluminum alloy AA5049 that were reinforced with microadditions of MWCNTs and MWCNTs coated with TiC nanoparticles were successfully produced. The microstructural and mechanical properties of the Al/MWCNT composites were investigated. The results showed that, on the one hand, the TiC nanoparticles on the surface of the MWCNT hybrid reinforcement reduced the damage of reinforcement under the intense exposure of milling bodies, and on the other hand, they reduced the contact area of the MWCNTs with the matrix material (acting as a barrier interface), which also locally inhibited the reaction between the matrix and the MWCNTs.

Flexible Liquid Sensor Based on Rubber/Graphite Composite

2020 ◽  
Vol 18 (4) ◽  
pp. 246-252
Author(s):  
Mohammad Khabiri ◽  
Milad Saadat Tagharoodi ◽  
Mohammad Reza Pourhossainy ◽  
Mashhood Abbasi ◽  
Mohamoud Razavizade
Keyword(s):  
Electrical Resistance ◽  
Hydrocarbon Fuel ◽  
Electrical Insulation ◽  
Polymer Swelling ◽  
Graphite Composite ◽  
Conductive Composite ◽  
Graphite Particles ◽  
Three Samples ◽  
Rubber Composite ◽  
Conductive Fillers

Hydrocarbon liquids such as gasoline, diesel, jet fuel, and solvents are hazardous materials derived from petroleum. These materials can diffuse the rubber network structures and cause swelling in these polymers. Rubber materials containing conductive fillers exhibit a high conductivity at the higher percolation threshold. As direct effect of solvent on the polymer, swelling in the rubber composite alters the structure of the filler network and subsequently the composite properties change significantly. This Process can be considered as a signal for solvent or hydrocarbon fuel detector system and used conductive rubber composite as a flexible sensor. In this study, the nitrile/graphite composite samples were prepared containing different amounts of graphite particles. These samples have the ability to measure electrical resistance. The electrical resistance of rubber/graphite samples decreases with increasing content of graphite particles. The increase in the electrical resistance of the specimens was measured by using conductive composite swelling in toluene solvent and it was observed that all specimens eventually became electrical insulation. Samples with concentrations of 60, 70, and 80 phr are conductive after recovery and solvent removal. While their conductivity is less than that of the virgin samples. The incremental trend of electrical resistance against the conductive composite swelling was measured in toluene solvent and it was observed that all samples were eventually converted to electrical insulation. But there is little difference between the third swelling process and the second one. This phenomenon has occurred for all three samples, which reveals a good similarity with the Mullins effect.

scholarly journals Tuneable PTC effect in polymer-wax-carbon composite resistors

2014 ◽  
Vol 31 (3) ◽  
pp. 143-148 ◽  
Author(s):  
Thomas Maeder ◽  
Caroline Jacq ◽  
Ludivine Ammon ◽  
Perer Ryser
Keyword(s):  
Organic Matrix ◽  
Carbon Composite ◽  
Phase Changes ◽  
Positive Temperature ◽  
Graphite Composite ◽  
Content Type ◽  
Ptc Effect ◽  
Crystalline Polymers ◽  
The Matrix ◽  
Ternary Polymer

Purpose – The purpose of this paper is to study tuneable positive temperature coefficient (PTC) effect in polymer-wax-carbon composite resistors. The resistivity dependence on temperature of composite resistors made of carbon fillers dispersed in an organic matrix is known to be strongly affected by the matrix thermal expansion. High PTC effects, i.e. essentially switching from resistive to quasi-insulating behaviour, can be caused by phase changes in the matrix and the assorted volume expansion, a behaviour that has been previously shown with both simple organic waxes and semi-crystalline polymers. However, waxes become very liquid on melting, possibly resulting in carbon sedimentation, and tuneability of semi-crystalline polymers is limited. Design/methodology/approach – The authors therefore study a ternary polymer-wax-conductor (ethylcellulose-octadecanol-graphite) composite resistor system, where polymer and wax fuse to a viscous liquid on heating, and re-solidify and separate by crystallisation of the wax on cooling. Findings – It is shown that with appropriate formulation, the resulting resistors exhibit strong PTC effects, linked with the melting and crystallisation of the wax component. The behaviour somewhat depends on sample history, and notably cooling speed. Research limitations/implications – The phase equilibria and transformation kinetics of the polymer-wax system (including possible wax polymorphism), as well as the exact mechanism of the conductivity transition, remain to be investigated. Originality/value – As many compatible polymer-wax systems with different melting/solidification behaviours are available, ternary polymer-wax-conductor composite PTC resistors allow a high tuneability of properties. Moreover, the high viscosity in the liquid state should largely avoid the sedimentation issues present with binary wax-conductor systems.

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