scholarly journals Effect of sintering temperature and porosity on electro- deoxidation of calcium titanate in CaCl2-NaCl molten salt

2022 ◽  
pp. ArticleID:220245
Author(s):  
Guoli Zhao ◽  
2017 ◽  
Vol 17 ◽  
pp. 88-95 ◽  
Author(s):  
L. John Bercmans ◽  
T. Sornakumar ◽  
A. Harish Kumar ◽  
G. Siva ◽  
G. Venkatesh

Alkaline earth titanates and zirconates and their binary systems are of interest for their temperature in sensitive dielectric properties. Calcium titanate and calcium zirconate perovskite ceramics find applications in pulse discharge, energy storage and microwave capacitors. These dielectric materials have been used in electric hybrid and fuel cell vehicles. In the present work, fine crystalline compound powders of calcium titanate and calcium zirconate were prepared by a single step molten salt synthesis. Calcium oxide and titanium dioxide/zirconium oxide were used as precursors to obtain the calcium titanate and calcium zirconate compound powders respectively. The prepared calcium titanate and calcium zirconate compound powders were characterized by TGA, FTIR, XRD, SEM and EDS analysis.


2012 ◽  
Vol 630 ◽  
pp. 89-92
Author(s):  
Yong Xing Zhang ◽  
Xue Ying Nai ◽  
Ming Wei ◽  
Dong Hai Zhu ◽  
Cheng Cai Zhu ◽  
...  

Well dispersive and single crystal calcium titanate (CaTiO3) whisker with a length of 50-100μm was synthesized by sintering the mixture of calcium chloride and titanium dioxide with improvement of adding the mineralization agent of Pb(Ac)2.3H2O. The as-prepared samples were characterized by XRD, SEM. The optimum synthesis condition and the effect of the mineralization agent were discussed respectively. In the end, the possible reaction process was given and a LS growth mechanism was proposed.


2016 ◽  
Vol 718 ◽  
pp. 129-132
Author(s):  
Chompoonuch Warangkanagool

In the research, the properties of potassium sodium niobate – barium titanate [(1-x)K0.02Na0.98NbO3–(x)BaTiO3: (1-x)KNN–(x)BT] ceramics prepared by molten salt method with various molecular weight of BT or x are 0 and 0.05 were investigated. The calcined powders of pure K0.02Na0.98NbO3 and (0.95) K0.02Na0.98NbO3-(0.05) BaTiO3 were pressed and sintered at 1250 – 1325 °C and 1225 – 1300 °C for 2h, respectively. It was found that, the samples showed phase structure changing from monoclinic to orthorhombic with small amount BaTiO3 addition. The densification of K0.02Na0.98NbO3 ceramics and dielectric properties were improved with the addition of BaTiO3. The (0.95)K0.02Na0.98NbO3–(0.05)BaTiO3 ceramics sintered at 1250 °C showed maximum density and dielectric constant (∼8035), which was even comparable with that of K0.02Na0.98NbO3 ceramics sintered at 1225 – 1300 °C.


2019 ◽  
Vol 805 ◽  
pp. 65-70
Author(s):  
Suchittra Inthong ◽  
Denis Russell Sweatman ◽  
Sukum Eitssayeam ◽  
Tawee Tunkasiri

This research is concerned with the effect of sintering temperature on physical and mechanical properties. This Hydroxyapatite-calcium titanate (HA-CT) composites were synthesized using conventional route technique. The HA-CT composites were sintered between 1200 up to 1300 °C. The effect of sintering temperature on the physical and mechanical properties of HA-CT composites was discussed. The physical properties were studied in term of densification and apparent porosity. As well as, the mechanical properties were determined in term of Vickers microhardness. The increasing of the sintering temperature increased both of the bulk density and the Vickers microhardness properties. However, the apparent porosity was decreased with increasing sintering temperature. The highest bulk density was found at 0.15 mol.% of CT in HA-CT composites which was sintered at 1300 °C for 3 h. Moreover, the mechanical properties as a function of the sintering temperature and the CT contents were also discussed and compared with other related work.


2018 ◽  
Vol 283 ◽  
pp. 132-139
Author(s):  
Chompoonuch Warangkanagool

In this study, the physical properties, dielectric properties, and micro-hardness of (Ba0.90Ca0.10)0.90(Na0.50Bi0.50)0.10TiO3 or BCT-NBT ceramics prepared by molten salt method with various sintering temperatures were investigated. The powders were calcined at 500-1100°C for 4 h with heating rate of 5°C/min. It was found that the optimum calcination condition was 1000°C for 4 h. These powders were pressed and sintered at 1200-1400°C for 3 h with a heating rate of 5°C/min. The microstructure was examined by scanning electron microscope (SEM). The density of the sintered samples was measured by Archimedes method with distilled water as the fluid medium. Dielectric properties were examined by LCR meter. The micro-hardness of the BCT-NBT ceramics was determined using the Vickers and Knoop indentation techniques. The results showed that the average grain sizes increased with increasing sintering temperatures. At sintering temperatures higher than 1200°C, the fracture mode changed from partial intra-granular to mainly intra-granular. The sintering temperature at which the density, dielectric and hardness properties were maximal was 1350°C. The highest density was about 5.4 g/cm3, and the Vickers and Knoop micro-hardnesses were 6.6 and 6.4 GPa, respectively. The dielectric constant at the Curie temperature was 3682 and the dielectric loss was 0.01 at 1 kHz frequency.


2007 ◽  
Vol 26-28 ◽  
pp. 239-242 ◽  
Author(s):  
Chun Wei Cui ◽  
Jin Liang Huang ◽  
Lin Hua Gao ◽  
Xing Hua Yang ◽  
Xiao Wang

Textured SrBi2Nb2O9 (SBN) ceramics were fabricated by templated grain growth (TGG) method. The plated-like SBN particles with shape anisotropy prepared by molten salt method were used as the templates. The SBN powders prepared by conventional solid (CS) reaction were used as matrix powders. It was found that the textured SBN ceramics can be obtained by TGG method. The grain orientation (Lotgering factor, f) increased with the increase of sintering temperature and content of the templates. The textured SBN ceramics with f=0.86 could then be obtained after sintering at 1300 °C for 3 h with 20wt.% templates. The relative density keeps rising with increasing temperature until it reaches a peak value 91.22% at the sintering temperature 1300°C, after which it decreases.


2015 ◽  
Vol 655 ◽  
pp. 141-146
Author(s):  
Xin Guan ◽  
Xiang Yun Deng ◽  
Jian Hao ◽  
Guang Hao Sun ◽  
Chuang Jun Huang

Barium calcium titanate (Ba0.96Ca0.04)(Zr0.05Ti0.95)O3 ferroelectric ceramics were prepared by sol–gel technique. The ceramics were sintering at 1290°C-1370°C. X-ray diffraction was employed to investigate the microstructure, and the surface topography was investigated by SEM graphs. The dielectric constant vs temperature was measured by Temperature dielectric spectrometer, and TF Analyzer 2000 measured the ferroelectric properties. It can be found that all the ceramics show pure perovskite structure suggesting that solid solution were formed. SEM showed that the samples uniform in grain size at 1330 °C. Our study revealed that when the sintering temperature is 1330 °C the maximum dielectric constant was 29,600, the maximum piezoelectric coefficient d33 could reach 399pm/V and the remanent polarization (Pr) was 8.3 μc/cm2, respectively.


2014 ◽  
Vol 881-883 ◽  
pp. 1045-1048
Author(s):  
Ding Guo ◽  
Jun Ding ◽  
Cheng Ji Deng ◽  
Hong Xi Zhu ◽  
Xiao Jun Zhang ◽  
...  

Using the natural forsterite and Na2CO3 as a raw material, the forsterite lightweight material was prepared in Na2CO3 molten salt. The reaction between forsterite and Na2CO3 and sintering mechanism of forsterite were studied in the paper. The sintering temperature was 1000 °C, 1100 °C, and the holding time was 1 h, 3 h, 5 h, 7 h, 10 h, respectively. The sintered samples were characterized by XRD and SEM for their microstructure and phase composition analysis which determined the mechanism of the chemical reaction and sintering in the sintering process. The product of Na2MgSiO4 phase in In earlier period of the reactions promoted the rearrangement of particles of forsterite in the initial stage of sintering process. The sintering mechanism was mainly controlled by the diffusion mechanism.


2013 ◽  
Vol 591 ◽  
pp. 194-199
Author(s):  
Tian Hang Zhang ◽  
Yan Gai Liu ◽  
Cheng Xue Yang ◽  
Jin Qiu Zhao ◽  
Zhao Hui Huang ◽  
...  

Sr2KNb5O15 ceramic powders have been synthesized by molten salt method, ceramics were sintered via a pressureless sintering method. The effect of calcining temperature on the phase composition and microstructure of ceramic powders were investigated by XRD and SEM analysis. The results show that microstructure of ceramic powders changed from acicular to platy, and the average size of ceramic powders become bigger with the calcining temperature increased. The optimal calcining temperature was 1200°C, and the length and diameter of ceramic powders was about 1-5 mm and 0.2-1 mm, thus the aspect ratio of ceramic powders was about 1-5. The influence of sintering temperature on density, microstructure and electrical properties of the ceramics were systematically analyzed. The results indicate that density and electrical properties of the ceramics first increased then decreased with increasing the sintering temperature. When the sintering temperature was 1400°C, the ceramics show optimized relative density and electrical properties (d33=40 pC/N, er=616, tand=0.029, Ec=9.83 kV/cm, Pr=32.50 mC/cm2).


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