Reactive silicon infiltration of carbon bonded preforms embedded in powder field modifiers heated by microwaves

Bianchi, Giovanni; Vavassori, P.; Vila, Brais; Annino, G.; Nagliati, Marco; Mallah, Marcel; Gianella, Sandro; Valle, Massimiliano; Orlandi, Marco; Ortona, Alberto

doi:10.1016/j.ceramint.2015.06.087

Cited by 12 publications

(9 citation statements)

References 20 publications

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“…The purpose of the inner crucible is to avoid the spreading of molten silicon into the susceptor powder chamber during the RMI process. As described in the group's previous work, the SiC‐BN powder optimizes microwaves diffusion‐absorption and thermally insulates the inner crucible. Solid silicon flakes (grit size of 0.2‐2.0 mm) were placed at the bottom of the inner crucible (E).…”

Section: Methodsmentioning

confidence: 99%

“…The rotation facilitates the homogeneous absorption of the MW. Further details on the furnace and its working parameters can be found in Ref . A digital camera integrated into the dual wavelengths pyrometer (PYROSPOT DSR10N; DIAS Infrared Systems GmbH) was used to align the BN tube of the setup with the rotation axis of the turning plate to allow a reliable temperature reading.…”

Section: Methodsmentioning

confidence: 99%

“…The experience gained on RMI by MW heating led us to design a versatile procedure to process different graphite preforms . In this work, this setup is used to study the influence of the heating treatment on RMI by changing the power supplied.…”

Section: Introductionmentioning

confidence: 99%

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Microwave heating controlled reactive melt infiltration for graphite‐Si‐SiC ceramics manufacturing

et al. 2018

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In this work, we investigated a procedure which exploits microwave ovens to produce SiC-based components by reactive melt infiltration of silicon into graphite preforms. The employed oven is designed to grant optical access to the sample surface, which allows to measure its temperature evolution though a noncontact pyrometer. This signal was used as a feedback to control the power provided to the preform and as an experimental output whose analysis provides insight into the reaction mechanism. Specifically, it is found that complete infiltration is achieved much before the end of the reaction. The latter is not fully self-sustained as the global reaction rate continuously decreases with time until it is no more able to keep the temperature above the silicon solidification value. At that point, the reaction stops. The analysis of the processed samples proved that this procedure allows producing fully infiltrated samples without material failure by adjusting the heat provided during the infiltration stage rather than by tuning the preform structure and composition, which is the usual approach. The proposed method is less time and energy consuming than the standard one.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Microwave heating controlled reactive melt infiltration for graphite‐Si‐SiC ceramics manufacturing

et al. 2018

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“…Out of all the procedures available, liquid-phase reactive infiltration has proven to be the most promising to obtain almost non-porous and large SiC pieces. During the liquid silicon infiltration (LSI) of a carbon porous preform, silicon readily reacts with the carbon skeleton during the infiltration to produce SiC [5,[7][8][9][10]. The benefits are a minimization of the working temperature and processing time while improving the product quality and the shape control.…”

Section: Introductionmentioning

confidence: 99%

Mechanisms and kinetics during reactive infiltration of molten silicon in porous graphite

Roger

Chollon

2019

Ceramics International

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Liquid silicon Infiltration (LSI) is a fast and economical process to manufacture SiC-based ceramics. For a better understanding of reactive melt infiltration of liquid silicon, the wetting and infiltration of porous graphite by molten silicon were investigated at 1450, 1500 and 1550°C for duration comprised between 10 s and 1 h. Infiltrations tests were performed in an argon atmosphere with an inductively heated furnace operating with heating and cooling rates of 300°C.min -1 . The formation and growth of SiC grains were investigated at the outer surface and within graphitic carbon substrates with 11% porosity and a narrow pore size distribution centered at 2 µm. The length of the infiltrated zone and the SiC crystals growth were determined from scanning electron microscopy. Rapid spreading and infiltration of molten silicon are observed from the first 60 seconds. The growth rate of the interfacial SiC layer obeys a fourthpower law with an activation energy of 26030 kJ.mol -1 . Pore filling by SiC is limited by volume diffusion with an activation energy equal to 32040 kJ.mol -1 .

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“…The latter presents an outstanding resistance to oxidation while maintaining an excellent thermal conductivity, low thermal expansion coefficient, low density and good mechanical properties. Cf/SiC composites are usually prepared by reactive infiltration, which consists of infiltrating molten Si into a C f /C porous preform [12,13]. As Si infiltrates the preform it reacts with the carbon to form a dense SiC matrix.…”

Section: Introductionmentioning

confidence: 99%

Effects of Fe addition on the mechanical and thermo-mechanical properties of SiC/FeSi2/Si composites produced via reactive infiltration

Camarano

Caccia

Molina

et al. 2016

Ceramics International

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Cite this article as: A. Camarano, M. Caccia, J.M. Molina and J. Narciso, Effects of fe addition on the mechanical and thermo-mechanical properties of SiC/FeSi 2 /si composites produced via reactive infiltration, Ceramics International, http://dx. ABSTRACT:Remaining silicon in SiC-based materials produced via reactive infiltration limits their use in high-temperature applications due to the poor mechanical properties of silicon: low fracture toughness, extreme fragility and creep phenomena above 1000ºC. In this paper SiC-FeSi2 composites are fabricated by reactive infiltration of Si-Fe alloys into porous Cf/C preforms. The resulting materials are SiC/FeSi2 composites, in which remaining silicon is reduced by formation of FeSi2. For the richest Fe alloys (35 wt.% Fe) a nominal residual silicon content below 1% has been observed. However this, the relatively poor mechanical properties (bending strength) measured for those resulting materials can be explained by the thermal mismatch of FeSi2 and SiC, which weakens the interface and does even generate new porosity, associated with a debonding phenomenon between the two phases.

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Reactive silicon infiltration of carbon bonded preforms embedded in powder field modifiers heated by microwaves

Cited by 12 publications

References 20 publications

Microwave heating controlled reactive melt infiltration for graphite‐Si‐SiC ceramics manufacturing

Microwave heating controlled reactive melt infiltration for graphite‐Si‐SiC ceramics manufacturing

Mechanisms and kinetics during reactive infiltration of molten silicon in porous graphite

Effects of Fe addition on the mechanical and thermo-mechanical properties of SiC/FeSi2/Si composites produced via reactive infiltration

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