scholarly journals The Study of the Thermal Treatment on the Surface Microstructure and Electrical Conductivity of the Copper/Graphite Composites

2019 ◽  
Vol 136 (3) ◽  
pp. 400-404
Author(s):  
Ž. Kavaliauskas ◽  
R. Kėželis ◽  
V. Valinčius ◽  
M. Milieška ◽  
A. Iljinas
2014 ◽  
Vol 604 ◽  
pp. 249-253 ◽  
Author(s):  
Agnese Pura ◽  
Janis Locs ◽  
Liga Berzina-Cimdina

TiO2samples were obtained by extrusion process, sintered in air at 1000 °C, 1100 °C, 1200°C and 1300 °C and, afterwards, thermally treated under vacuum conditions at 1250 °C for 1 hour applying two different heating/cooling rates (2 °C/min and 5 °C/min). It was found that thermal treatment conditions substantially affected thermoelectric properties of the samples. Increasing sintering temperature, during the sample thermal treatment in air, the electrical conductivity of the specimens increased, while Seebeck coefficient decreased. With an increase in the heating rate during the vacuum heat treatment of the samples, the electrical conductivity of the samples decreased, while Seebeck coefficient increased.


Author(s):  
Yaroslav KOVALYSHYN ◽  
◽  
Ivanna TERENYAK ◽  
Orest PEREVIZNYK ◽  
◽  
...  

Modified thermally exfoliated graphite with p-nitrophenyldiazonium tetrafluoroborate, followed by reduction of nitrophenyl groups to aminophenyl ones. Composites PAN - graphite, PAN - modified graphite at a constant value of potential 1 V were synthesized by electrochemical method. Their conditional density and electrical conductivity were determined. The electrochemical behavior in 1 M HCl solution was investigated and the capacity of synthesized composites was calculated. The conditional density of PAN composites with modified and non modified graphite increases sharply with increasing graphite content from 0 to 5%. At graphite contents higher than 5%, the density of composites varies very slightly. In the range of graphite contents 0% - 20%, the density is the highest for composites with a graphite content of 5% - 10%. In the case of modified graphite, the density of composites is higher than that of composites with non modified graphite. Analysis of the dependence of the specific conductivity on the content of modified graphite indicates that the conductivity of PAN - graphite composites increases the most with increasing graphite content from 1 to 10%. In this interval, the conductivity increases linearly. This indicates the absence of specific interactions between the components in the synthesized composites, as well as the fact that the nature of the distribution of these components does not change with changes in the graphite content. For a composite with modified graphite, there are two maximum capacities of composites with a graphite content of 2 and 10%. For a composite with non modified graphite on the obtained curves there is a maximum capacity of composites with a graphite content of 2%. Modification of the graphite surface leads to increased interaction between the components of the compo¬site, which resulted in the compaction of its structure. As a result, the capacitive characteristics of modified graphite composites, as well as CVA currents and electrical conductivity, were lower compared to composites with non modified graphite.


2014 ◽  
Vol 11 (2) ◽  
pp. 131-138
Author(s):  
Inga Narkevica ◽  
Jurijs Ozolins ◽  
Kristaps Rubenis ◽  
Janis Kleperis ◽  
Janis Locs ◽  
...  

The influence of thermal treatment conditions on titanium dioxide ceramics phase transformation, microstructure, physico-mechanical and electrical properties was studied. TiO2 ceramic was prepared using extrusion technology and thermal treatment in air and subsequent annealing under high vacuum conditions. It has been observed that intense TiO2 ceramic mass sintering occurs over the temperature ranging from 950 °C to 1100 °C. It is accompanied by crystallographic modification change from anatase to rutile. Ceramic sample annealing in vacuum causes formation of nonstoichiometric titanium oxide ceramics and as a result electrical conductivity of the material significantly increases. Using extrusion process relatively dense and mechanically resistant ceramic material can be obtained that can be used in different technological processes.


RSC Advances ◽  
2016 ◽  
Vol 6 (31) ◽  
pp. 25776-25779 ◽  
Author(s):  
Shoji Nozato ◽  
Akira Nakasuga ◽  
Takuya Wada ◽  
Hiroshi Yoshitani ◽  
Hirotaka Ihara

This paper introduces a new carbon material having high electrical conductivity and dispersibility, which is characterized by a partially exfoliated structure with grafted polymer and restacking ability through removal of the grafted polymer.


RSC Advances ◽  
2015 ◽  
Vol 5 (113) ◽  
pp. 93267-93273 ◽  
Author(s):  
Eunsil Lee ◽  
Ki Beom Choi ◽  
Sung-Min Lee ◽  
Jong-Young Kim ◽  
Jong-Yeol Jung ◽  
...  

We present a facile one-pot synthesis of alumina/exfoliated graphite composite having excellent electrical conductivity (>1,000 S m−1), fracture toughness (5.6 MPa m0.5), and wear resistance, which is enhanced by 7.7 times compared to pure alumina.


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