scholarly journals Influence of metal impurities on erosis and wearing of composite contacts

2020 ◽  
pp. 86-96
Author(s):  
A. Mrachkovskyi ◽  
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Physical And Mechanical Properties ◽  
Electrical Contacts ◽  
Reference Points ◽  
Contact Material ◽  
Working Surface ◽  
Electric Erosion ◽  
Diffusion Migration ◽  
Switching Devices

The questions of influence of contact material, switching modes and environment with various impurity on electroerosion resistance of contact details of switching devices are considered. Substantiated possibilities and measures to increase the reliability and efficiency of relays in electrical installations through agriculture through the use of erosion-resistant contact materials based on the study of physical and mechanical properties of the components of the composite contact material in switching current; substantiated composition of ingredients in the new composite material for contact parts of switching devices. The results of researches of electro erosive stability of composite material depending on structure of ingredients and their physical and mechanical properties are resulted. It has been experimentally established and theoretically confirmed that electric erosion is mainly determined by the microstructure of the material and the change in the physical and mechanical properties of the ingredients on the working surface of the contact parts during current switching. Factors providing increased arc resistance due to thermoemission properties of contact compositions that control the processes of diffusion, migration and phase transformations in chemical reactions are obtained, and the theory of the mechanism of arc reference points movement on the working surface of electrical contacts is substantiated.

scholarly journals Features of arc discharges and erosion phenomena

2021 ◽  
pp. 135-145
Author(s):  
A. Mrachkovskyi ◽  
◽  
O. Solovei ◽  
Keyword(s):  
Low Voltage ◽  
Physical And Mechanical Properties ◽  
Electrical Contacts ◽  
Reference Points ◽  
Work Surface ◽  
Working Surface ◽  
Electrical Devices ◽  
Electric Erosion ◽  
Diffusion Migration ◽  
The Cost

Low-voltage electrical appliances play an important role in ensuring the control of energy processes, protection and switching of electrical circuits. Problems that occur in low-voltage electrical devices at rated currents of 32 - 1000 A, relate to electrical contacts that determine the operation of electrical devices. The main contribution to the development of erosion of the working surface is made by an electric arc, which is formed in the inter-contact gap when opening electrical contacts. In world practice, existing solutions to increase the arc resistance of electrical contacts do not completely solve the problem of reducing erosion of their work surface. The use of additional devices in arc suppression systems leads to an increase in the size of electrical devices. The use of expensive and toxic elements in the compositions leads to an increase in the cost of electrical appliances and poisoning of the environment. Strengthening the composition of the contacts through the use of refractory elements leads to an increase in the transient resistance. The aim of the study was to substantiate and develop the main provisions of the theory of processes and phenomena that occur on the work surface and in the electrode areas of electrical contacts, and to create compositions of high arc contact compositions for switching electrical devices. The theory of the mechanism of movement of arc reference points on the working surface of electrical contacts is substantiated and the factors providing increased arc resistance due to thermoemission properties of contact composition compositions that control diffusion, migration and phase transformations during chemical reactions are obtained. It has been experimentally established and theoretically confirmed that electric erosion is mainly determined by the microstructure of the material and the change in the physical and mechanical properties of the ingredients on the working surface of the contact parts during current switching. Key words: anode, cathode, erosion, contact wear, working surface, arc column, arc resistance, transient resistance

Influence of Portland Cement Addition in the Physical and Mechanical Properties of Epoxy Resin

2015 ◽  
Vol 1088 ◽  
pp. 411-414 ◽  
Author(s):  
Francisco Augusto Zago Marques ◽  
Carlos Eduardo G. da Silva ◽  
André Luis Christoforo ◽  
Francisco Antonio Rocco Lahr ◽  
Túlio Hallak Panzera ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Composite Material ◽  
Portland Cement ◽  
Physical Properties ◽  
Epoxy Resin ◽  
Modulus Of Elasticity ◽  
Epoxy Matrix ◽  
Physical And Mechanical Properties ◽  
Response Variable

This research evaluated, with the of the analyses of variance (ANOVA), a composite material based on epoxy matrix phase reinforced with Portland cement (CP-II) particles (0%wt [100%wt of resin], 20%wt, 40%wt, 60%wt). The response-variable investigated were modulus of elasticity (E) and compressive strength (S), bulk density (ρB), apparent density (ρA) and porosity (P). The highest values of the modulus of elasticity were provided from the composites manufactured with 40wt% of cement addition. The inclusion of 60% of cement implies in a reduction in the mechanical properties when compared with the results of the composite manufactured with 40% of cement. For the physical properties, the gradually inclusion of cement provides increasing in the density of the composites, and reduce the porosity of the materials manufactured.

Physical and Mechanical Properties of Glass Composite Material Made from Incinerated Scheduled Waste Slag and SLS Waste Glass

2012 ◽  
Vol 626 ◽  
pp. 280-288 ◽  
Author(s):  
Jariah Mohd Juoi ◽  
Dilip Arudra ◽  
Zulkifli Mohd Rosli ◽  
A.R. Toibah ◽  
Siti Rahmah Shamsuri ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Water Absorption ◽  
Physical And Mechanical Properties ◽  
Waste Glass ◽  
X Ray Diffraction ◽  
Glass Composite ◽  
X Ray ◽  
Land Site ◽  
Waste Loading

Incineration of scheduled waste and landfilling of the incineration residue (Bottom Slag) is extensively practised in Malaysia as a treatment method for scheduled waste. Land site disposal of Bottom Slag (BS) may lead to environmental health issues and reduces the availability of land to sustain the nations development. This research aims in producing Glass Composite Material (GCM) incorporating BS and Soda Lime Silicate (SLS) waste glass as an alternative method for land site disposal method and as an effort for recycling SLS waste glass .SLS waste glass originates from the urban waste and has been a waste stream in most of the nation whereby the necessity for recycling is in high priority.The effect of BS waste loading on the GCM is studied.Batches of powder mixture is formulated with 30 wt% to 70 wt % of BS powder and SLS waste glass powder for GCM sintering.The powder mixtures of BS and SLS waste glass is compacted by uniaxial pressing method and sintered at 800C with heating rate of 2C/min and 1 hour soaking time. Physical analysis of bulk density, apparent porosity, and water absorption is perfomed according to ASTM C-373 standard. Mechanical testing of microhardness vickers according to ASTM C1327 and Modulus of Rupture (MOR) according to ISO 10545-4 is conducted. Microstructural analysis is carried out using Scanning Electron Microscope and phase analysis by X-ray diffraction method.Phases identified are Anorthite sodian,Quartz,Hematite and Diopside from X-ray diffraction analysis. Higher BS waste loading shows weak physical and mechanical properties .GCM from batch formulation of 30 wt % BS and 70 wt% SLS waste glass has projected optimized physical and mechanical properties. It is observed this batch has projected lowest water absorption percentage of 1.17 % , lowest porosity percentage of 2.2 %, highest bulk density of 1.88 g/cm3and highest MOR of 70.57 Mpa and 5.6 GPa for Vickers Microhardness.

scholarly journals Synthesis and Properties of Electroconductive Polymeric Composite Material Based on Polypyrrole

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
N. S. Ilicheva ◽  
N. K. Kitaeva ◽  
V. R. Duflot ◽  
V. I. Kabanova
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Mechanical Strength ◽  
Process Parameters ◽  
Physical And Mechanical Properties ◽  
Polymeric Composite ◽  
Polymeric Composite Material ◽  
Elastic Composite ◽  
The Relationship

A technique is proposed for obtaining electroconductive, mechanically strong, and elastic composite material based on polypyrrole and hydrophilized polyethylene. The relationship is established between the process parameters and properties of the composite material such as electroconductivity and mechanical strength. Several methods are considered in the view of increasing electroconductivity of the material. Physical and mechanical properties of the composite material are investigated.

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