Effect of Sintering Temperature and Particle Size on Porous SiC/Si3N4 Composite Ceramics

2011 ◽  
Vol 399-401 ◽  
pp. 449-452
Author(s):  
Shuo Wang ◽  
Jun Li ◽  
Wen Jie Yuan ◽  
Hong Xi Zhu ◽  
Cheng Ji Deng
Keyword(s):  
Mechanical Property ◽  
Particle Size ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Composite Ceramic ◽  
Composite Ceramics ◽  
Different Temperatures ◽  
Porous Sic ◽  
Microstructure And Mechanical Property ◽  
Compressive Tests

Porous SiC/Si3N4 composite ceramic was prepared at different temperatures by pressureless using SiC and Si3N4 as raw materials. The effects of sintering temperature and different particle size of SiC on porosity SiC/Si3N4 composite ceramic were investigated. The phases, microstructure and mechanical property were characterized by XRD, SEM, and compressive tests respectively. The results indicate that the increase of sintering temperature is in favor of the formation of β-Si3N4 crystal phase, the porosity and the compression strengthof porous SiC/Si3N4 composite ; The porosity of Si3N4/SiC block which contain particle graded higher than single particle size, but weaker compression strength.

Study on Mechanical Property of Al2O3-Based Composite Ceramics Liner of Heavy-Medium Cyclone

2011 ◽  
Vol 295-297 ◽  
pp. 581-584
Author(s):  
Li Qiang Zhang ◽  
Ping Huo ◽  
Yong Huang ◽  
Peng Li ◽  
Rong Yang
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Mechanical Property ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Composite Ceramics ◽  
Heavy Medium ◽  
Scanning Electron

In laboratory condition, industrial zirconia and alumina were used as raw materials, whose particle size was controlled by ultrafine treatment of mechanical milling. The effects of different firing temperatures and soaking times on mechanical properties of Al2O3-based composite ceramics liner were researched. And the microstructure of samples was studied by scanning electron microscopy (SEM). The results indicate that mechanical properties of samples kept 3 h at sintering temperature of 1600°C with adding 30 wt% zirconia are the best.

Effect of Sintering Temperatures on the Reaction-Bonded Si3N4/SiC Composite Ceramics

2011 ◽  
Vol 399-401 ◽  
pp. 331-335 ◽  
Author(s):  
Jun Li ◽  
Wen Jie Yuan ◽  
Shuo Wang ◽  
Hong Xi Zhu ◽  
Cheng Ji Deng
Keyword(s):  
Compressive Strength ◽  
Raw Materials ◽  
Silicon Powder ◽  
Processing Parameters ◽  
Nitrogen Atmosphere ◽  
Particle Sizes ◽  
Composite Ceramics ◽  
Strength Tests ◽  
Different Temperatures ◽  
Microstructure And Mechanical Property

Effect of sintering temperatures on reaction-bonded Si3N4/SiC composite ceramics under pressureless was investigated. Si3N4/SiC composite ceramics were sintered at different temperatures from 1450 to 1700 °C under nitrogen atmosphere by using SiC with different particle sizes, Si and additives Y2O3 as raw materials. The phases, microstructure and mechanical property were characterized by XRD, SEM, and compressive strength tests. The results demonstrated that when the particle gradation consists of silicon carbide of 74 μm (5 wt.%), 44 μm (10 wt.%) and 0.5 μm(35 wt.%) and silicon powder of 74 μm (42 wt.%), the more dense samples with the bulk density of 2.43 g/cm3 and the higher compressive strength of 324 MPa could be obtained at the sintering temperature of 1550 °C for 3h as the optimum processing parameters.

Effects of Micropores on Processing and Properties of Porous Irons

2017 ◽  
Vol 863 ◽  
pp. 26-32
Author(s):  
Ming Zhou Su ◽  
Hui Meng Wang ◽  
Chang Chen
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Corn Starch ◽  
Sintering Temperature ◽  
Starch Content ◽  
Volumetric Shrinkage ◽  
Small Particle Size ◽  
Compressive Properties ◽  
Different Temperatures ◽  
Powder Metallurgy Route

Porous irons with only micropores were produced through powder metallurgy route. Corn starch of small particle size (5-15μm) was utilized to regulate the densification of green compacts. The structural and mechanical properties of porous irons sintered at different temperatures were evaluated. The porosities increased with increasing the starch content, which reduced compressive strength and increased volumetric shrinkage. The compressive yield stress increased with increasing sintering temperature. It was also found that the effect of sintering temperature on the microstructure and compressive properties was more obvious when green compacts were less densified. Moreover, volumetric shrinkage of porous irons without adding starch remains in a quite low level for different sintering temperatures.

Effects of Polarization Treatment on Mechanical Properties of Al2O3/LiTaO3 Composite Ceramics

2007 ◽  
Vol 353-358 ◽  
pp. 1314-1317
Author(s):  
You Feng Zhang ◽  
Qing Chang Meng ◽  
De Chang Jia ◽  
Yu Zhou
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Domain Switching ◽  
Composite Ceramic ◽  
Polarization Direction ◽  
Composite Ceramics ◽  
Pressing Method ◽  
Width Direction ◽  
Different Temperatures ◽  
Polarization Temperature

The Al2O3/LiTaO3 (ALT) composite ceramics were fabricated by hot pressing method and polarization treated at different temperatures along height and width directions. Effects of polarization treatment on mechanical properties of the ALT composite ceramic were investigated. Flexural strength decreased with the increase of polarization temperature. Meanwhile, the flexural strength of samples polarized in height direction is higher than that polarized in width direction. The composite ceramic fractures intragranularly, and many rupture steps in polarization direction were observed on fractographs of the composite ceramics. Domain switching in LiTaO3 particles increased the resistance of crack propagation and improved the mechanical properties of the polarized ALT composite ceramics.

Preparation and Properties of CaF2 Nano-Powder

2016 ◽  
Vol 680 ◽  
pp. 257-260
Author(s):  
Meng Yun Dong ◽  
Cheng Zhang ◽  
Jin Feng Xia ◽  
Hong Qiang Nian ◽  
Dan Yu Jiang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Sintering Temperature ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nano Powder ◽  
Direct Precipitation ◽  
Scanning Electron

CaF2 nano-power was prepared by direct precipitation methods with Ca(NO3)2 and KF as raw materials. The influences of presintering temperature and sintering temperature on the particle size and distribution of CaF2 nano-power were studied by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM). This study provided an experimental method for preparation of CaF2 nano-power. The results show that the best presintering temperature of CaF2 nano-power is 500°C and the best sintering temperature of CaF2 ceramic is 900°C.

A Process for Sintering of Diopside Prepared from Dolomite

2005 ◽  
Vol 492-493 ◽  
pp. 235-240 ◽  
Author(s):  
S. Zouai ◽  
F.Z. Mezahi ◽  
S. Achour ◽  
Abdelhamid Harabi
Keyword(s):  
Sintering Temperature ◽  
Raw Materials ◽  
Egg White ◽  
Different Temperatures ◽  
Pure Sio2

Diopside CaMgSi2O6 is an attractive material because of its multi applications. It was prepared by sintering the mixture at different temperatures (900°C-1300°C). Starting materials were pure SiO2 and dolomite raw materials. In order to improve the properties of sintered samples, such as the density egg white (ovalbemin) has been added into diopside. Furthermore, the effect of P2O5 addition on the sintering of the prepared diopside in the range of 0.5 to 5.0 wt% was studied as a function of the sintering temperature. A density of 96.5% of theoretical has been achieved when 5.0 wt% P2O5 was added, at a sintering temperature of 1225°C, whereas the density of diopside samples, without P2O5 addition was lower than 83.0% of theoretical.

Porous SiO2/SiC Fiber Via Carbothermal-Reduction of Hybrid Fiber in Air Flows

2011 ◽  
Vol 236-238 ◽  
pp. 1492-1496
Author(s):  
Qiu Sheng Song ◽  
Kai Zhang ◽  
Shun Xu ◽  
Zhen Biao Zhong ◽  
Meng Li
Keyword(s):  
Sintering Temperature ◽  
Raw Materials ◽  
Sol Gel ◽  
Drawing Process ◽  
Hybrid Fiber ◽  
Hybrid Fibers ◽  
Air Atmosphere ◽  
Sic Fiber ◽  
Different Temperatures ◽  
Ft Ir

Using tetraethoxysilane (TEOS) and novolac-PF as raw materials, SiO2/PF hybrid fibers were prepared via sol-gel associated with drawing process, and then sintered at different temperatures (500-1300 °C) under air atmosphere. The microstructure variation and reaction mechanism of the fiber were investigated by FT-IR, XRD, and SEM measurements. The results showed that the microstructure variation of the hybrid fiber was influenced greatly by sintering temperatures. When the sintering temperature was below 900 °C, the fibers were amorphous, and converted into porous SiO2/SiC fibers after being sintered at 1300 °C.

scholarly journals Effects of oxidation of SiC aggregates on the sintering behaviour and microstructures of SiC-CaAl12O19 composite refractories

2021 ◽  
Vol 15 (1) ◽  
pp. 11-18
Author(s):  
Yaochen Si ◽  
Miao Xia ◽  
Hongxia Li ◽  
Honggang Sun ◽  
Ang Guo ◽  
...  
Keyword(s):  
Firing Temperature ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Coal Slurry ◽  
Refractory Materials ◽  
Sintering Process ◽  
Active Oxidation ◽  
Passive Oxidation ◽  
Different Temperatures ◽  
Sintering Behaviour

In order to develop chrome-free refractory materials applicable in coal slurry gasification, SiC-CaAl12O19 (SiC-CA6) composite refractories were developed and prepared by using SiC aggregates and CA6 powders as main raw materials. The sintering behaviour of the composites was investigated. After firing at different temperatures under CO atmosphere, the effects of oxidation of SiC aggregates on the sintering behaviour and microstructures of SiC-CA6 composite refractorieswere investigated. SiC-CA6 composites could not be sintered when firing temperature was lower than 1500?C. SiC had a passive oxidation and the oxidation components were able to react with CA6 to form CaAl2Si2O8. The CaAl2Si2O8 melted into liquid when sintering temperature was in the range of 1500-1600?C, which promoted the sintering process of the SiC-CA6 composites. At temperatures above 1600 ?C, an active oxidation of SiC occurred. Simultaneously, SiC could also reacted with the SiO2(s,l) to form SiO, leading to the precipitation of Al2O3 and CaO in the liquid to generate plate-like CA6. Above this temperature, the sintering of the SiC-CA6 composite refractories was affected by the growth of CA6 and oxidation of SiC. This work demonstrates that the optimal sintering temperature for the SiC-CA6 composite refractories was 1600?C.

Effects of different sintering temperature on structural and magnetic properties of Ni–Cu–Co ferrite nanoparticles

2018 ◽  
Vol 32 (27) ◽  
pp. 1850321 ◽  
Author(s):  
Xiaoguang Pan ◽  
Aimin Sun ◽  
Yingqiang Han ◽  
Wei Zhang ◽  
Xiqian Zhao
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Spinel Structure ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Stable State ◽  
Precursor Solution ◽  
Auto Combustion ◽  
Different Temperatures ◽  
Ft Ir

In this work, sol–gel auto-combustion technology is used to synthesize nanocrystalline Ni[Formula: see text]Cu[Formula: see text]Co[Formula: see text]Fe2O4 with high purity metal nitrate and citric acid as precursor solution. The prepared samples are sintered at different temperatures (400[Formula: see text]C, 500[Formula: see text]C, 600[Formula: see text]C, 700[Formula: see text]C, 800[Formula: see text]C, 900[Formula: see text]C, 1000[Formula: see text]C and 1100[Formula: see text]C) for 3.5 h. The structure and magnetic properties of the samples are characterized using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and vibrating sample magnetometer (VSM). The analysis of the XRD patterns confirms that all the samples have a single-phase cubic spinel structure. The particle size of the prepared samples (between 23 nm and 36 nm) is determined by the Scherrer equation. The effect of particle size is through observation of samples sintered at different temperatures. FT-IR spectroscopy shows the characteristic peak is near 588 cm[Formula: see text]. And the measurement also confirms the formation of spinel structure. The magnetic parameters of the samples are measured by VSM at room temperature with a maximum magnetic field of 1 T. Coercivity, remanent magnetization and saturation magnetization change with the changing sintering temperature. It can be clearly observed that the magnetic properties increase significantly with the temperature increasing from 600[Formula: see text]C to 700[Formula: see text]C. The dM/dH versus H curves are obtained by differentiating the hysteresis loop. The increasing peak height of dM/dH at [Formula: see text], indicates a magnetically stable state for the samples with good crystalline cubic spinel structure.

Thermal Conductivity of Biomorphic Porous SiC Based Ceramics

2010 ◽  
Author(s):  
Nadejda Popovska ◽  
Emad Alkhateeb ◽  
Tanja Kugler ◽  
Andreas P. Fro¨ba ◽  
Alfred Leipertz
Keyword(s):  
Thermal Conductivity ◽  
Single Phase ◽  
Porous Ceramic ◽  
Chemical Vapor ◽  
Composite Ceramic ◽  
Laser Flash ◽  
Ceramic Composites ◽  
Chemical Vapor Infiltration ◽  
Composite Ceramics ◽  
Porous Sic

Biomorphic porous SiC composite ceramics were produced by chemical vapor infiltration and reaction (CVI-R) technique using paper preforms as template. The thermal conductivity of four samples with different composition and microstructure was investigated: a) C-template b) C-SiC, c) C-SiC-Si3N4 and d) SiC coated with a thin layer of TiO2. The SiC-Si3N4 composite ceramic showed enhanced oxidation resistance compared to single phase SiC. However; a key property for the application of these materials at high temperatures is their thermal conductivity. The later was determined experimentally at defined temperatures in the range 298–373K with a laser flash apparatus. It was found that the thermal conductivity of the porous ceramic composites increases in the following order: C-template < C-SiC < C-SiC-Si3N4 < SiC-TiO2. The results were interpreted in regard to the porosity and the microstructure of the ceramics.

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