Development of Pressureless Sintering Method for Carbon Nanotube/Alumina Composites and Their Microstructure-Property Relationships

In this paper, using ZrO2 and Ca (NO3)•4H2O as raw materials, we prepared a series of calica stabilized zirconia (CSZ) ceramics by pressureless sintering method. The results show that the relative densities of all sintered samples are above 90%, and the sintered samples are composed of cubic, tetragonal and monoclinic ZrO2, and the main phase is cubic ZrO2 and tetragonal ZrO2. The content of cubic phase increases with the increase of sintering temperature and adding CaO content. The grain size of the sintered samples is relatively uniform and some pores exist. Increasing the additive amount of CaO, the conductivity first rises and then decreases, and the conductivity value of the sample containing 5wt% CaO is the maximum. When the sintering temperature is up to 1600 oC, the conductivity of the sample containing 5wt% CaO is up to 0.016S•cm-1 at 800 oC. Furthermore, the conductivity of sintered samples is increasing with the increase of test temperature according to the Arrhenius equation.

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Preparation and Microstructure of Pressureless Sintered Si2ON2-SiC Ceramic

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.335-336.699 ◽

2011 ◽

Vol 335-336 ◽

pp. 699-703

Author(s):

Hui Hui Tan ◽

Zhu Xing Tang ◽

Xia Zhao ◽

He Zhang

Keyword(s):

Bulk Density ◽

Sintering Temperature ◽

Pressureless Sintering ◽

Nitriding Temperature ◽

X Ray Diffraction ◽

X Ray ◽

Effect Of Additives ◽

Sic Ceramic ◽

Sintering Method ◽

Scanning Electron

This paper introduces Si2ON2-SiC ceramic fabricated by pressureless sintering method and studies the effect of additives, nitriding temperatures on bulk density, porosity, phase composition and microstructure. It is discovered that additives MgO, CeO2 can increase the densities of Si2ON2-SiC ceramic apparently, and MgO additive has a better effect than CeO2. Nitriding temperature also is an important factor. The bulk density of the specimen with MgO additive reaches maximum at 1.91 g/cm3 when sintered at 1450 °C, and the bulk density of specimen with CeO2 additive is 1.86 g/cm3 at the same condition while the bulk density of the specimen without additive is only 1.75 g/cSuperscript textm3. The X-ray diffraction and scanning electron microscopy of the specimens show that the amount of Si2ON2 increase with the sintering temperature increase. But when the temperature is higher than 1500 °C the Si2ON2 grains will decompose into Si3N4, and Si2ON2 will vanish at 1550 °C

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Preparation and Investigation on Properties of the MgTiO3-CaTiO3 Microwave Ceramic Materials

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.997.419 ◽

2014 ◽

Vol 997 ◽

pp. 419-423 ◽

Cited By ~ 1

Author(s):

Li Dong ◽

Gui Xia Dong ◽

Yuan Yuan Li ◽

Xi Zhang

Keyword(s):

Dielectric Constant ◽

Sintering Temperature ◽

Ceramic Materials ◽

Volume Density ◽

Second Phase ◽

Pressureless Sintering ◽

Solid Reaction ◽

Reaction Method ◽

Microwave Ceramic ◽

Sintering Method

The MgTiO3 and CaTiO3 powders were synthesized by solid reaction method, and MgTiO3-CaTiO3 ceramic was prepared using pressureless sintering method. The experiment prepared MgTiO3-CaTiO3 ceramics with high compactness and stable permittivity by the way of changing the mole ratio of MgTiO3 and CaTiO3 to investigate the effect of CaTiO3 on the performances of MgTiO3-CaTiO3 ceramics. The results show that Mg2TiO4 formed as second phase during sintering. Volume density and dielectric constant of MgTiO3-CaTiO3 ceramics with 10%mol CaTiO3 reach maximum of 3.612g/cm3 and 17.8, respectively, under 1460°C sintering temperature. And for the MgTiO3-CaTiO3 ceramics with 5%mol CaTiO3 the maximum values which are 3.5g/cm3 and 16.6, respectively, appear under 1510°C sintering temperature.

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