Study on Electrical and Thermal Properties of Epoxy Resin/Inorganic Filler Composites for the Fully Enclosed Casting Bus Bar and its Calculation of the Temperature Field

2014 ◽  
Vol 804 ◽  
pp. 191-194 ◽  
Author(s):  
Nai Kui Gao ◽  
Yi Li Wang ◽  
Wen Xi Zhang ◽  
Zhao Liu ◽  
Chi Chen ◽  
...  

This paper focused on the epoxy resin/inorganic filler composites. The electrical and thermal properties of the composites were tested and analyzed at room temperature. The influence of temperature on the thermal conductivity and thermal expansion coefficient was studied. Based on the electrical and thermal properties of the composites, the simulation model of the fully enclosed epoxy resin casting bus bar (FEERCB) was built, and the temperature field distribution of the FEERCB was calculated. T The study results showed that the volume resistivity, dielectric constant, dielectric loss factor and breakdown strength of the epoxy resin/inorganic filler composites were 1.74×1014Ω·cm, 3.44, 3.75 and 22.31 kV/mm respectively at room temperature. The thermal conductivity and thermal expansion coefficient of the composites were 2.55 W/m·K and 21.73×10-6 /°C, achieved the insulation requirements for FEERCB. In the temperature range of the test, with increasing temperature, the thermal conductivity reduced gradually, while the thermal expansion coefficient increased gradually. The simulation results showed that the FEERCB has remarkable performance on the heat dissipation and current carrying capability.

2012 ◽  
Vol 512-515 ◽  
pp. 469-473 ◽  
Author(s):  
L. Liu ◽  
Z. Ma ◽  
F.C. Wang ◽  
Q. Xu

According to the theory of phonon transport and thermal expansion, a new complex rare-earth zirconate ceramic (La0.4Sm0.5Yb0.1)2Zr2O7, with low thermal conductivity and high thermal expansion coefficient, has been designed by doping proper ions at A sites. The complex rare-earth zirconate (La0.4Sm0.5Yb0.1)2Zr2O7 powder for thermal barrier coatings (TBCs) was synthesized by coprecipitation-calcination method. The phase, microstructure and thermal properties of the new material were investigated. The results revealed that single phase (La0.4Sm0.5Yb0.1)2Zr2O7 with pyrochlore structure was synthesized. The thermal conductivity and the thermal expansion coefficient of the designed complex rare-earth zirconate ceramic is about 1.3W/m•K and 10.5×10-6/K, respectively. These results imply that (La0.4Sm0.5Yb0.1)2Zr2O7 can be explored as the candidate material for the ceramic layer in TBCs system.


1958 ◽  
Vol 25 (4) ◽  
pp. 525-528
Author(s):  
H. Tramposch ◽  
G. Gerard

Abstract The optical and physical properties of Paraplex P43, Castolite, and epoxy resin Hysol 6000-OP, which are potentially of interest in photothermoelastic investigations, were investigated over a temperature range from +100 to −60 F. Results on the thermal-expansion coefficient, the material fringe value, and the modulus of elasticity as functions of temperature are presented. Also evaluated were thermal properties of importance in heat conduction. Photothermoelastic figures of merit, which rate the optical sensitivity of materials in photothermoelastic applications, as well as a new method to determine this figure in a relative manner are presented.


2007 ◽  
Vol 1043 ◽  
Author(s):  
Masayoshi Uno ◽  
Ken Kurosaki ◽  
Shinsuke Yamanaka ◽  
Kazuo Minato

AbstractWe made various nitride fuels containing simulated FP elements and evaluated the effect of these FP elements on the properties of the nitrides. For Uranium Neodymium nitride solid solution the lattice parameter increased with Nd content, thermal expansion coefficient did not change and thermal conductivity decreased with Nd content. The thermal expansion for Pd containing UN, where Pd precipitated as UPd3 in the grain boundaries of UN, was nearly the same as that of UN and the thermal conductivity for Pd containing in the UN matrix decreased with Pd content. For Mo containing UN Mo precipitated as Mo metal isotropically. Both the thermal expansion and thermal conductivity did not vary with Mo content This might result from the low Mo contents at these simulated burnups.


2018 ◽  
Vol 50 (4) ◽  
pp. 401-408
Author(s):  
Chunwei Leng ◽  
Xiaojun Hu ◽  
Hongliang Xie ◽  
Chunhua Shen

The excellent thermal and chemical properties of cubic boron nitride (cBN) indicate that it is potential materials to prepare the thermal dissipate substrate applied in the electronic packaging. The thermal properties of polycrystalline cBN ceramics, however, have not been fully investigated. We report the first sintering experiment on preparing polycrystalline cBN ceramics using cBN powder as starting material without any sintering aids. The microstructure and high bending strength show that the strong combination was achieved among the crystal grains. The measured results, including density, thermal conductivity and thermal expansion coefficient, reveal that the properties of this ceramics depend on the grain size of starting crystal cBN. The PcBN ceramics has low thermal expansion coefficient extremely matching to that of silicon and exhibits moderate thermal conductivity due to its low density and the existence of low thermal conductive phase of hexagonal boron nitride.


1985 ◽  
Vol 38 (4) ◽  
pp. 617 ◽  
Author(s):  
JG Collins ◽  
SJ Collocott ◽  
GK White

The linear thermal expansion coefficient a from 2 to 100 K and heat capacity per gram cp from 0�3 to 30 K are reported for fully-stabilized zirconia containing a nominal 16 wt.% (9 mol.%) of yttria. The heat capacity below 7 K has been analysed into a linear (tunnelling?) term, a Schottky term centred at 1�2 K, a Debye term (e~ = 540 K), and a small T5 contribution. The expansion coefficient is roughly proportional to T from 5 to 20 K and gives a limiting lattice Griineisen parameter 'Yo ::::: 5, which agrees with that calculated from elastic data.


2013 ◽  
Vol 752 ◽  
pp. 48-56
Author(s):  
Andrea Simon ◽  
Károly Kovács ◽  
C. Hakan Gür ◽  
Tadeusz Pieczonka ◽  
Zoltán Gácsi

Composites are special material which can provide individual properties such as high strength with low density or good thermal conductivity with low thermal expansion coefficient. Composites conform to the constantly evolving and more complex expectations. In order to make a product with good quality, it is important to choose suitable materials and technology. In this research powder metallurgy (PM), as one of the most common composite manufacturing technology, was examined -which factors and mechanisms influence mostly the properties of the product. Ishikawa method was used to reveal these correlations.


Author(s):  
Jianhua Yu ◽  
Huayu Zhao ◽  
Shunyan Tao ◽  
Xiaming Zhou ◽  
Chuanxian Ding

Plasma-sprayed thermal barrier coating (TBC) systems are widely used in gas turbine blades to increase turbine entry temperature (TET) and better efficiency. Yttria stabilized zirconia (YSZ) has been the conventional thermal barrier coating material because of its low thermal conductivity, relative high thermal expansion coefficient and good corrosion resistance. However the YSZ coatings can hardly fulfill the harsh requirements in future for higher reliability and the lower thermal conductivity at higher temperatures. Among the interesting TBC candidates, materials with pyrochlore structure show promising thermo-physical properties for use at temperatures exceeding 1200 °C. Sm2Zr2O7 bulk material does not only have high temperature stability, sintering resistance but also lower thermal conductivity and higher thermal expansion coefficient. The sintering characteristics of ceramic thermal barrier coatings under high temperature conditions are complex phenomena. In this paper, samarium zirconate (Sm2Zr2O7, SZ) powder and coatings were prepared by solid state reaction and atmosphere plasma spraying process, respectively. The microstructure development of coatings derived from sintering after heat-treated at 1200–1500 °C for 50 h have been investigated. The microstructure was examined by scanning electron microscopy (SEM) and the grain growth was analyzed in this paper as well.


2012 ◽  
Vol 490-495 ◽  
pp. 3266-3271
Author(s):  
Yan Xia Li ◽  
Jun You Liu ◽  
Guo Quan Liu ◽  
Wen Shao Wang

50vol. %Si/Al composite was prepared by the separation of liquid and solid in semi-solid. The microstructures of composite were obtained using OM, SEM and EMPA. The primary Si particles distribute uniformly on the Al matrix which surrounds the Si particles and makes-up a continuous network. The thermal expansion coefficient and thermal conductivity of composites experienced different thermal process were examined. It shows that the thermal process history has a significant effect on the microstructure and properties. The residual stress and size of Si particles varied during thermal processing which were responsible for the thermal expansion coefficient alternation. The thermal process of high temperature insostatic pressing reduces the porosity in composite and improves thermal conductivity obviously


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