• Transactions on Electrical and Electronic Materials
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• v.7 no.3
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• pp.134-140
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• 2006

The effect of surface treatment of fillers on the mechanical, electrical properties, and tracking performance of silicone rubber insulators have been investigated. For base polymer, $\alpha,\;\omega$) vinyl poly(dimethyl-methylphenyl) siloxane(VPMPS) containing dimethyl siloxane and methylphenyl siloxane was prepared by the equilibrium polymerization. High voltage silicone rubber composites(HVSRC) were prepared from VPMPS, nano-silica, and alumina trihydrate (ATH) modified by various coupling agents. Bound rubber of uncured silicone rubber, cross-linking density of the vulcanizate as well as the mechanical, electrical properties, and tracking performance were measured.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.226-229
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• 1999

Epoxy compound has been used as insulation material in electrical equipment for a long time because of its excellent electrical, mechanical and chemical properties. Nowdays, becoming higher voltage system, the properties of interface between epoxy and metal insert become more important. The breakdown voltage of epoxy compound for electric material is variable according to the surface roughness of metal insert. Generally, with metal insert sanding, the adhesion strength is enhanced and the breakdown strength is reduced. But in this study, we knew that the adhesion strength became enhanced but the breakdown strength didn\`t reduced with metal insert sanding. So in this study sanding. So in this study, we suggest the optimum interface condition by adjusting the surface roughness.

• Transactions on Electrical and Electronic Materials
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• v.17 no.3
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• pp.155-158
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• 2016

The effect of microsilica content modified with silicone-modified epoxy on electrical and mechanical properties of cycloaliphatic epoxy/microsilica system was investigated. The cycloaliphatic epoxy resin was diglycidyl 1,2-cyclohexanedicarboxylate and curing agent was an anhydride. Surface of microsilica was modified with silicone-modified epoxy. Electrical breakdown strength, the most important property for electrical insulation materials was tested. Tensile and flexural tests were also performed using universal testing machine (UTM). The microcomposite with 60 wt% microsilica shows maximum values in electrical breakdown strength.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.514-517
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• 2003

Polymeric suspended insulators for subway and electrical track line had been designed and manufactured. The main elements to design polymeric insulators were the insulation ability and the optimal structure. To get the insulation ability, electrical and mechanical tests according to standards had done on housing rubbers and FRP cores and selected the sample with best properties as a insulator. The insulator shape and fitting parts with minimum electrical stress was simulated by FEM electrical field analysis program. The manufactured insulator set had been tested and estimated the electrical and mechanical according to ES and KS, and showed good characteristics in these tests.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.12
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• pp.2995-3002
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• 2000

The remaining life estimation for the aged components in power plants as well as chemical plants are very important beacuse mechanical properties of the components are degraded with time of service exposure in high temperature. Since it is difficult to take specimens from the operating components to evaluate mechanical properties of components nondestructive techniques are needed to estimate the degradation. In this study, test materials with 4 different degradation levels were prepared by isothermal aging heat treatment at 630$\^{C}$. And the DC potential drop method and destructive methods such as tensile, K(sub)IC and hardness tests were used in order to evaluate the degradation of 1-Cr-1Mo-0.25V steels. The objective of this study is to investigate the possibility of the application of DCPD method to estimated the material degradation, and to analyse the relationship between the electrical relationship between the electrical resistivity and the degree material degradation.

• Structural Engineering and Mechanics
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• v.73 no.3
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• pp.259-269
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• 2020

In this paper, bending-stretching analysis of thick functionally graded piezoelectric rectangular plates is studied using the higher-order shear and normal deformable plate theory. On the basis of this theory, Legendre polynomials are used for approximating the components of displacement field. Also, the effects of both normal and shear deformations are encountered in the theory. The governing equations are derived using the principle of virtual work and variational approach. It is assumed that plate is made of piezoelectric materials with functionally graded distribution of material properties. Hence, exponential function is used to modify mechanical and electrical properties through the thickness of the plate. Finally, the effect of material properties, electrical boundary conditions and dimensions are investigated on the static response of plate. Also, it is shown that results of the presented model are close to the three dimensional elasticity solutions.

• Korean Journal of Materials Research
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• v.30 no.6
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• pp.308-314
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• 2020

A commercial AA1070 alloy for electrical wire is severely deformed by drawing process in which a rod with an initial diameter of 9mm into is reduced to a wire of 2mm diameter. The drawn AA1070 wire is then annealed at various temperatures from 200 to 450 ℃ for 2h. Changes in microstructure, mechanical properties and electrical properties of the specimens with annealing temperature are investigated in detail. The specimen begins partially to recrystallize at 250 ℃; above 300 ℃ it is covered with equiaxed recrystallized grains over all regions. Fiber textures of {110}<111> and {112}<111> components are mainly developed, and {110}<001> texture is partially developed as well. The tensile strength tends to decrease with annealing temperature due to the occurrence of recovery or/and recrystallization. On the other hand, the elongation of the annealed wire increases with the annealing temperature, and reaches a maximum value of 33.3 % at 300 ℃. Electric conductivity of the specimens increases with annealing temperature, and reaches a maximum value of 62.6 %IACS after annealing at 450 ℃. These results are discussed in comparison with those for the other aluminum alloy.

• Transactions on Electrical and Electronic Materials
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• v.10 no.3
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• pp.97-101
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• 2009

The use of a filler material in epoxy composite materials is an essential condition for reducing the unit cost of production and reinforcing mechanical strength. However, the dielectric strength of insulators decreases rapidly due to interactions between the epoxy resin and filler particles. In contrast to existing composite materials, nano-composite materials have superior dielectric strength, mechanical strength, and enduring chemical properties due to an increase in the bond strength of the polymer and nano material, It is reported that nano-fillers provide new characteristics different from the properties of the polymer material. This study is to improve the insulation capability of epoxy resins used in the insulation of a power transformer apparatus and many electronic devices mold. To accomplish this, the additional amount of nano-$SiO_2$ to epoxy resin was changed and the epoxy/$SiO_2$ nano composite materials were made, and the fundamental electrical properties were investigated using a physical properties and an analysis breakdown test. Using allowable breakdown probability, the optimum breakdown strength for designing an electrical apparatus was determined. The results found that the electrical characteristics of the nano-$SiO_2$ content specimens were superior to the virgin specimens. The 0.4 wt% specimens showed the highest electrical properties among the specimens examined with an allowable breakdown probability of 20 %, which indicates stable breakdown strength in insulating machinery design.

• Transactions on Electrical and Electronic Materials
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• v.12 no.4
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• pp.135-139
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• 2011

In an effort to develop new electrical insulation materials, four different kinds of organically modified layered silicate were incorporated into an epoxy matrix to prepare nanocomposites for electrical insulation. Five wt% of organically modified layered silicates were processed in a planetary centrifugal mixer in an epoxy matrix, and the thermal, mechanical, and electrical properties of the cured epoxy/layered silicate were investigated. The morphology of the nanoscale silicate dispersed in the epoxy matrix was observed using transmission electron microscopy, and the interlayer distance was measured by wide-angle X-ray scattering diffraction analysis.

• International Journal of Advanced Culture Technology
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• v.3 no.1
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• pp.46-51
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• 2015

The mechanical and electrical properties of aluminium alloy 6061 are reported in this present work. Aluminium alloys were homogenized at $550^{\circ}C$, for 5 hours and cooled in the furnace. The different thickness reductions of 60-90% on homogenized aluminium alloy plates were achieved by cryo-rolling. Later, the as rolled samples were aged by solution treatment at the temperatures of $520^{\circ}C$ for 1 hour, water quenched; subsequently aged at $160^{\circ}C$ for 8-24 hours and partial aged (not solution treatment) at $160^{\circ}C$ for 8- 24 hours. Mechanical and electrical properties of samples were investigated. The experimental result showed that the microhardness of cryo-rolled samples were increase with increasing the percentage of the thickness reduction. Moreover, the microhardness of cryo-rolled, aged by solution treatment samples were higher than those of the cryo-rolled and cryo-rolled, partial aged samples. The cryo-rolled alloys subjected to full aged at $160^{\circ}C$ for 24 hours exhibited the hardness of 125 HV and electrical conductivity values was 45.76 %IACS and the cryo-rolled alloys subjected to partial aged at $160^{\circ}C$ for 20 hours exhibited the hardness of 67 HV and electrical conductivity values was 49.67 %IACS.