Electrical conductivity and thermal stability measurements of a mixed perovskite oxide system

1982 ◽  
Vol 53 (5) ◽  
pp. 3686-3689 ◽  
Author(s):  
Mary H. Sukkar ◽  
Donald R. Sadoway
2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Qingzhong Mao ◽  
Yusheng Zhang ◽  
Yazhou Guo ◽  
Yonghao Zhao

AbstractThe rapid development of high-speed rail requires copper contact wire that simultaneously possesses excellent electrical conductivity, thermal stability and mechanical properties. Unfortunately, these are generally mutually exclusive properties. Here, we demonstrate directional optimization of microstructure and overcome the strength-conductivity tradeoff in copper wire. We use rotary swaging to prepare copper wire with a fiber texture and long ultrafine grains aligned along the wire axis. The wire exhibits a high electrical conductivity of 97% of the international annealed copper standard (IACS), a yield strength of over 450 MPa, high impact and wear resistances, and thermal stability of up to 573 K for 1 h. Subsequent annealing enhances the conductivity to 103 % of IACS while maintaining a yield strength above 380 MPa. The long grains provide a channel for free electrons, while the low-angle grain boundaries between ultrafine grains block dislocation slip and crack propagation, and lower the ability for boundary migration.


2005 ◽  
Vol 176 (25-28) ◽  
pp. 2167-2170 ◽  
Author(s):  
P SINGH ◽  
O PARKASH ◽  
D KUMAR

1969 ◽  
Vol 42 (2) ◽  
pp. 418-440 ◽  
Author(s):  
R. M. Russell ◽  
T. D. Skinner ◽  
A. A. Watson

Abstract It was shown in Part I that the use of EV systems in NR provides a simple network in which the crosslinks are mainly monosulfidic. Part II describes in some detail the properties of vulcanizates obtained by the use of EV systems and their relationship to conventional and TMTD-zinc oxide cured vulcanizates. The disadvantages of short scorch time and heavy bloom which accompany the TMTD-zinc oxide system are overcome by the new EV systems. The monosulfidic network obtained by the use of EV systems confers on NR good overall physical properties together with much improved resistance towards thermal and thermal oxidative aging. The thermal stability of this type of network is reflected in the outstanding resistance of the vulcanizates to set and reversion, and their good resistance to heat build-up under dynamic conditions. Vulcanizates derived from EV systems have increased resistance to thermal oxidative aging due to the inherent thermal stability of the networks and good response to antioxidant protection. This increased resistance results in much better retention of tensile properties, tear resistance and fatigue cracking resistance on aging, relative to that of conventionally cured vulcanizates.


2021 ◽  
Author(s):  
Tushar Kanti Bhowmik ◽  
Md Sariful Sheikh ◽  
Anup Pradhan Sakhya ◽  
Alo Dutta ◽  
T. P. Sinha

RSC Advances ◽  
2015 ◽  
Vol 5 (34) ◽  
pp. 26998-27002 ◽  
Author(s):  
Chang Hyo Kim ◽  
Moo Sung Kim ◽  
Yoong Ahm Kim ◽  
Kap Seung Yang ◽  
Seung Jo Baek ◽  
...  

Carbon fibers are considered as one of the promising heating elements in various industrial applications because of their excellent thermal stability and electrical conductivity.


2018 ◽  
Vol 29 (3) ◽  
pp. 1019-1028 ◽  
Author(s):  
Mohammad Mizanur Rahman Khan ◽  
Nurfarahhana Binti Daud ◽  
Mohammad Shahadat Hussain Chowdhury ◽  
Wan Ahmad Kamil Mahmood ◽  
Hisatoshi Kobayashi

2015 ◽  
Vol 3 (7) ◽  
pp. 3602-3611 ◽  
Author(s):  
Nicola H. Perry ◽  
Jae Jin Kim ◽  
Sean R. Bishop ◽  
Harry L. Tuller

To evaluate stability in energy conversion devices, thermal and chemical expansion coefficients (CTE, CCE) of Sr(Ti,Fe)O3−α were measured and deconvoluted for the first time, revealing an oxygen stoichiometry-dependent CTE and temperature-dependent CCE.


BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 3408-3426
Author(s):  
Fateme Rezaei ◽  
Rabi Behrooz ◽  
Shahram Arbab ◽  
Ehsanollah Nosratian Sabet

Bacterial cellulose was selected as a potential precursor for the production of carbon nanofiber because of its high purity and crystallinity. Diammonium phosphate ((NH4)2HPO4) as a flame retardant was used to impregnate the cellulosic nanofiber sheet precursor in order to increase its thermal stability during the thermal processing. Also, the effect of heating rate on the stabilization and carbonization processes of cellulosic nanofiber samples was investigated. The precursor and resulted carbon nanofiber sheets were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and electrical characteristics. The results showed that the simultaneous usage of flame retardant (diammonium phosphate) and low heating rate in the stabilization process (2 °C min-1) increases thermal stability of cellulosic nanofiber sheets and the carbon yield. The presence of a flame retardant acts like a low heating rate effect but does not significantly affect the high heating rate of the stabilization process. As carbonization temperature increased, electrical conductivity and crystallite size were increased for impregnated samples. The carbonization process at 1200 °C, with a heating rate of 2 °C min-1, makes bacterial cellulose precursor an appropriate candidate for producing carbon nanofiber sheets with proper electrical characteristics.


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