Local mechanical characterisation and modelling of the interfacial behaviour in Hi-Nicalon/BN/α-Si3N4 ceramic matrix composites by way of instrumented microindentation tests

1998 ◽  
Vol 18 (13) ◽  
pp. 1845-1855 ◽  
Author(s):  
Monssef Drissi-Habti ◽  
Kikuo Nakano
Keyword(s):  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Matrix Composites ◽  
Si3n4 Ceramic ◽  
Mechanical Characterisation ◽  
Interfacial Behaviour

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.

Optimization of a Pyrolysis Procedure for Obtaining SiC-SiCf CMC by PIP for Thermostructural Applications

2012 ◽  
Vol 77 ◽  
pp. 153-158 ◽  
Author(s):  
Claudio Mingazzini ◽  
Alida Brentari ◽  
Federica Burgio ◽  
Emiliano Burresi ◽  
Matteo Scafè ◽  
...  
Keyword(s):  
Chemical Vapour ◽  
Ceramic Matrix Composites ◽  
Cost Effective ◽  
Ceramic Matrix ◽  
Pyrolytic Carbon ◽  
Matrix Composites ◽  
Mechanical Characterisation ◽  
Steel Furnace ◽  
Cost Effective Technique ◽  
Polymer Impregnation

Polymer Impregnation Pyrolysis (PIP) is a cost effective technique for obtaining Ceramic Matrix Composites (CMC) modified with nanoparticles. Commercial UBE polymeric precursor (Tyranno polymer VL-100, diluted in xylene) of a SiC ceramic matrix (with 11 wt% O and 2 wt% Ti) was used to infiltrate 100x85x3 mmSuperscript text3 SiC felts (Tyranno ZM fibers, diameter 14 microns, 800 filament/yarn, 270 g/mSuperscript text2, with 9 wt% O and 1 wt% Zr), applying different pyrolysis procedures. In particular, pyrolysis was performed in two conditions: 1) at 1000 °C for 60 min; 2) at 900 °C for 120 min. A pyrolysis at 900 °C could be more convenient since it can be easily performed in a steel furnace, without a refractory lining. The SiC felts were pretreated by CVD (Chemical Vapour Deposition) in order to deposit a pyrolytic carbon interphase (about 0.1 microns). Impregnation was performed under vacuum, and drying was carried out in an explosion-proof heating oven. Pyrolysis at 900°C was performed in a AISI 310S austenitic steel furnace, under nitrogen flow. Geometric density was monitored during densification. Mechanical characterisation (bending tests at room temperature, following UNI EN 658-3:2002) was performed after 11 PIP cycles. The results were used to compare the influence of pyrolysis temperature on densification.

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.

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