Thermodynamic and phase analysis of SiC-nano/microB4C-C composites produced by pressureless sintering method

2021 ◽  
Author(s):  
Behnam Salmany Kozekanan ◽  
Alireza Moradkhani ◽  
Hamidreza Baharvandi ◽  
Naser Ehsani
Keyword(s):  
Phase Analysis ◽  
Pressureless Sintering ◽  
Sintering Method

Preparation and Electrical Property of Calcia Stabilized Zirconia Ceramics

2014 ◽  
Vol 616 ◽  
pp. 157-165 ◽  
Author(s):  
Chang Lian Chen ◽  
Hong Quan Wang ◽  
Jia You Ji ◽  
Ma Ya Luo ◽  
Bo Wu ◽  
...  
Keyword(s):  
Grain Size ◽  
Electrical Property ◽  
Arrhenius Equation ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Cubic Phase ◽  
Pressureless Sintering ◽  
Stabilized Zirconia ◽  
Zirconia Ceramics ◽  
Sintering Method

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.

Preparation and Microstructure of Pressureless Sintered Si2ON2-SiC Ceramic

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

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

2014 ◽  
Vol 997 ◽  
pp. 419-423 ◽  
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.

SILICON CARBIDE SC-221

Alloy Digest ◽  
1991 ◽  
Vol 40 (7) ◽  
Keyword(s):  
Fracture Toughness ◽  
Silicon Carbide ◽  
High Temperature ◽  
Mechanical Strength ◽  
Physical Properties ◽  
Bending Strength ◽  
Beta Phase ◽  
Pressureless Sintering ◽  
Bend Strength ◽  
Sintering Method

Abstract SILICON CARBIDE SC-221 is a beta-phase silicon carbide made from the pressureless sintering method. It possesses excellent mechanical strength at high temperature (4-point bending strength of 71ksi [490 MPa] at 1400 C [2552 F]). This datasheet provides information on physical properties, hardness, elasticity, and bend strength as well as fracture toughness. Filing Code: Cer-5. Producer or source: Kyocera America Inc..

Densification and Mechanical Properties of Y-TZP/25 wt. % ZrB2 Composite

2012 ◽  
Vol 59 (2) ◽  
Author(s):  
E. M. Mahdi ◽  
S. Ramesh ◽  
M. Amiriyan ◽  
R. Tolouei ◽  
S. Meenaloshini ◽  
...  
Keyword(s):  
Materials Science ◽  
Sintering Temperature ◽  
Tetragonal Zirconia ◽  
Cost Effective ◽  
Argon Atmosphere ◽  
Pressureless Sintering ◽  
High Electrical Conductivity ◽  
Mechanics Of Materials ◽  
Processing Techniques ◽  
Sintering Method

Over the last three decades, most of the efforts in mechanics of materials science have been focused to develop tougher and stronger ceramics via cost effective processing techniques. In the present work, 3 mol % Yttria-stabilized tetragonal zirconia (3Y-TZP) composites with 25 wt. % of ZrB2 was prepared by pressureless sintering method in argon atmosphere over the temperature range of 1350-1550°C for one hour holding time. The influences of zirconium diboride addition in the zirconia matrix, as well as the sintering temperature, on the densification, phase stability and electrical properties of sintered samples have been studied. The results revealed that electrical resistivity values is very low (high electrical conductivity) when 25 wt. % of ZrB2 is incorporated to pure 3Y-TZP.

Preparation and Characterization of Polycrystalline Cubic Boron Nitride (PcBN) Compacts by a Pressureless Sintering Process

2010 ◽  
Vol 105-106 ◽  
pp. 38-41 ◽  
Author(s):  
Zhen Huo Ren ◽  
Rui Zhang ◽  
Hai Long Wang ◽  
De Liang Chen ◽  
Ming Liang Li
Keyword(s):  
Boron Nitride ◽  
Cubic Boron Nitride ◽  
Cost Effective ◽  
Sintering Behavior ◽  
Pressureless Sintering ◽  
X Ray Diffraction ◽  
Polycrystalline Cubic Boron Nitride ◽  
Air Atmosphere ◽  
Sintering Method

A novel cost-effective pressureless sintering method has been developed to prepare polycrystalline cubic boron nitride (PcBN) compacts. The effect of feldspar as sintering aids was analyzed in this paper. Various amounts of feldspar from 5 to 15 wt% were added to cBN powders, and the pressureless sintering was conducted at temperatures ranging from 900°C to 1200°C under an air atmosphere. The microstructure, phase, density and microhardness of the as-obtained PcBN compacts were measured and correlated to amounts of Si added and to sintering temperatures. The sample showed superior sintering behavior in comparison to those fabricated using hot pressed sintering. The results of X-ray diffraction (XRD) and scanning electron microscopy (SEM) showed that feldspar diffused homogeneously and tightly bonded with cBN. But hBN appeared when the sintering temperature even at 900°C, which dramatically affected the property of PcBN compacts. A PcBN compact with a relative density of 91% was obtained at 1100°C and its microhardness was as high as 1000HV.

The Effect of SiC Content on Pressureless Sintered Si2ON2-SiC Ceramic

2012 ◽  
Vol 562-564 ◽  
pp. 27-30
Author(s):  
Zhu Xing Tang ◽  
Hui Hui Tan ◽  
He Zhang ◽  
Ke Zhou Xu ◽  
Ying Zhang
Keyword(s):  
Silicon Carbide ◽  
Phase Composition ◽  
Silicon Oxynitride ◽  
Pressureless Sintering ◽  
Silicon Carbide Ceramic ◽  
Ceramic Samples ◽  
Sic Ceramic ◽  
Carbide Ceramics ◽  
Silicon Carbide Ceramics ◽  
Sintering Method

The Si¬2ON2-SiC ceramic was fabricated by pressureless sintering method. In this paper we researched the effect of SiC content (50%, 70% and 90%) on the performance of silicon oxynitride bonded silicon carbide ceramics. Through testing and analyzing the SEM, XRD, density and porosity of the final silicon oxynitride bonded silicon carbide ceramic samples, the results show that: changes in SiC content not only affect the bulk density of the composites but also affect the phase composition and the microstructure of fracture surface. The most compactness experimental product is sintered at1500°C containing 50wt% SiC.

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