CNTs/Si3N4 Composites Fabricated by Reaction Bonded Processing

2007 ◽  
Vol 336-338 ◽  
pp. 1277-1279
Author(s):  
Zhi Yong Huang ◽  
Xue Jian Liu ◽  
Xing Wei Sun ◽  
Li Ping Huang
Keyword(s):  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Xrd Analysis ◽  
Matrix Composites ◽  
Si3n4 Ceramic ◽  
Average Value ◽  
Microwave Attenuation ◽  
X Band ◽  
Sem Micrograph ◽  
Transmission Attenuation

The CNTs/Si3N4 ceramic matrix composites were prepared by the reaction bonded processing. The phase compositions, chemical compatibility, mechanical properties, and microwave attenuation properties of the composites were investigated. XRD analysis shows the composites consist mainly of the α- and β-Si3N4, with a trace of unreacted silicon. The SEM micrograph displays the fractured surface of the composites studs with intact CNTs, indicating that CNTs and Si3N4 are chemically compatible. The composites with 1.0wt.% CNTs have a strength of 280 MPa, hardness of 8.2 GPa and toughness of 2.3 MPa·m0.5. The average value of the transmission attenuation reaches 6 dB at X band, indicating the composites have a potential for application in electromagnetic adsorbing or shielding.

In Situ Synthesis of TiB2-TiCx Ceramic Matrix Composites by Hot Isostatic Pressing

2007 ◽  
Vol 26-28 ◽  
pp. 251-254
Author(s):  
De Gui Zhu ◽  
Hong Liang Sun ◽  
Liang Hui Wang
Keyword(s):  
Raw Materials ◽  
Hot Isostatic Pressing ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Xrd Analysis ◽  
In Situ Synthesis ◽  
Matrix Composites ◽  
Isostatic Pressing ◽  
Fine Grain

TiB2-TiC ceramic matrix composites were fabricated by in situ synthesis under hot isostatic pressing (HIP) with 3TiH2-B4C and 11TiH2-3B4C being the raw materials, respectively. The XRD analysis indicates that the samples synthesized from 3TiH2-B4C have TiB2 and TiC phases, while those from 11TiH2-3B4C have not only TiB2 and TiCx phases, but also Ti3B4 phase. TiB2-TiCx ceramic matrix composites obtained from 11TiH2-3B4C have better mechanical properties than those from 3TiH2-B4C. The microstructures of the composites are investigated with SEM and TEM. TiB2 grains are platelet grains; Ti3B4 grains have two different morphologies. Ti3B4 phases are formed through two different paths: fine grain Ti3B4 is formed through TiB+B=Ti3B4 at low temperature; large plate-like grain Ti3B4 is formed through TiB2+TiB=Ti3B4 at high temperature.

Electroconductive Ceramic Composites for Cutting Tools

2006 ◽  
Vol 514-516 ◽  
pp. 638-642 ◽  
Author(s):  
Flávia A. Almeida ◽  
Helena Bóia ◽  
Catarina Santos ◽  
Jorge Monteiro ◽  
Filipe J. Oliveira ◽  
...  
Keyword(s):  
Cost Reduction ◽  
Cutting Tools ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Ceramic Materials ◽  
Ceramic Composites ◽  
Matrix Composites ◽  
Si3n4 Ceramic ◽  
The Cost ◽  
Si3n4 Matrix

The addition of titanium nitride (TiN) particles to a Si3N4 matrix reduces the intrinsic electric resistivity of this ceramic allowing it to be machined by EDM in cutting tools manufacturing. Gains can be expected given the cost reduction by the increase of productivity when shaping these hard to machine ceramic materials. Si3N4 ceramic matrix composites (CMC’s) with 0- 30vol.% of TiN sub-micrometric particles were produced by uniaxial hot pressing (HP) and pressureless sintering (PS). For the PS samples, EDM tests showed that machining of the composites is possible when they contain at least 23vol.% TiN particles what corresponds to a resistivity of 7.5cm. For HP samples at least 30vol.% of TiN is required to get an electroconductive material for EDM machining. This difference is due to the lower temperatures used in the HP process that delay the formation of a conductive network between the TiN particles.

scholarly journals Influence of Graphene and Graphene Oxide on Properties of Spark Plasma Sintered Si3N4 Ceramic Matrix

Ceramics ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 40-50 ◽  
Author(s):  
Katalin Balazsi ◽  
Mónika Furkó ◽  
Piotr Klimczyk ◽  
Csaba Balázsi
Keyword(s):  
Graphene Oxide ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Uniaxial Pressure ◽  
Matrix Composites ◽  
Si3n4 Ceramic ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Short Time ◽  
Preferential Alignment

The sintering of ceramic matrix composites is usually carried out by raising the sintering temperature below the melting point of components. Spark plasma sintering (SPS) has the capability to densify ceramics at a relatively low temperature in a very short time. Two different additions, multilayered graphene (MLG) and graphene oxide (GrO), were added to Si3N4 ceramic matrix in various amount; 5 wt% and 30 wt%. The influence of reinforcing phase on final properties of spark plasma sintered Si3N4 composite was studied. The uniaxial-pressure-assisted SPS sintering resulted in a preferential alignment of both type of graphene in the Si3N4 ceramic matrix, leading to highly anisotropic properties with lower mechanical behavior but better tribological and electrical properties.

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