Electron probe microanalysis of Nicalon fibres

Bleay, Stephen M.; Chapman, A. R.; Love, G.; Scott, V. D.

doi:10.1007/bf02403848

Cited by 19 publications

(5 citation statements)

References 16 publications

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“…The di usion of silicon, carbon and oxygen from the ® bre to the matrix is controlled by gradients of activity between these. Several studies have subsequently shown that the ® bre is actually made up of SiC and carbon but that it also contains a signi® cant amount of silicon oxycarbide and very little SiO 2 (Lipowitz et al 1987, La on et al 1989, Porte and Sartre 1989, Bleay et al 1992.…”

mentioning

confidence: 98%

SiC Nicalon fibre-glass matrix composites: interphases and their mechanism of formation

Strat¹,

Lancin²,

Fourches-Coulon³

et al. 1998

Philosophical Magazine A

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The ® bre± matrix reaction that occurs during the processing of a Nicalon SiC ® bre± Pyrex glass matrix composite is analysed. Interphases are characterized by means of various complementary techniques: electron di raction, HRTEM, EDX, EELS, SIMS and XPS. Neither the results of the present study nor those previously obtained for Nicalon SiC ® bre± LAS (Li 2 O± Al 2 O 3 ± SiO 2) glass or LAS + MAS (MgO± Al 2 O 3 ± SiO 2 ) glass± ceramic matrix composites support the available model of reaction. An alternative reaction mechanism is suggested whereby the dissolved and non-bridging oxygen atoms of the matrix di use and oxidize SiC and SiO x C y in the ® bre. The reaction yields carbon and silicon oxycarbide in the ® bre and SiO 2 which dissolves into the matrix. When the oxygen in excess in the matrix is consumed, the reaction stops and the phases undergo a reorganization in the reaction layer which generates two interphases, one carbon rich and the other silicon oxycarbide rich. These interphases are observed at the ® bre periphery in all glass or glass± ceramic matrix composites. § 1. Introduction Glass or glass± ceramic matrix composites are developed for thermostructural applications such as in aircraft parts submitted to severe thermomechanical stresses. Glass± ceramic is reinforced by means of long ® bres that are essentially stronger and less brittle than the matrix. This reinforcement yields composites with high strength and a`pseudoplastic' strain su cient to alleviate the catastrophic rupture mode of a brittle material. Amongst commercial ® bres, the SiC Nicalon 202 ® bre has been successfully used in the last years. The mechanical properties of Nicalon± glass matrix composites depend on the nature of the interphases that develop during material processing (Brennan 1988, Lancin 1991. A good characterization of the reaction between the ® bre and the matrix together with the understanding of this reaction are essential in order to elaborate composites with required speci® cations.Studies of the interphases produced in the course of the ® bre± matrix reaction have been conducted in a number of composites based on various matrices (Brennan 1988, Chen et al. 1989, Bonney and Cooper 1990. The most currently used are Li 2 O-Al 2 O 3 -SiO 2 (LAS) or CaO± Al 2 O 3 -SiO 2 (CAS) containing some additives such as niobium, arsenic or yttrium. In order to explain the formation of interphases, one usually refers to the model proposed by Cooper and Chyung (1987) which

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mentioning

confidence: 98%

SiC Nicalon fibre-glass matrix composites: interphases and their mechanism of formation

Strat¹,

Lancin²,

Fourches-Coulon³

et al. 1998

Philosophical Magazine A

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“…The Si-C-O fibers are a mixture of b-SiC nanocrystals, free carbon, and an amorphous silicon oxycarbide SiC x O y phase. 11,13,[44][45][46][47] The microstructure of the Si-C fibers is a mixture of larger b-SiC crystallites, with larger amounts of glassy carbon, and a very small amount of SiC x O y phase in comparison with the Si-C-O fibers.…”

Section: Microstructure Of Si-c-o Fibers and Low-oxygenmentioning

confidence: 99%

SiC-Based Ceramic Fibers Prepared via Organic-to-Inorganic Conversion Process-A Review

清人¹,

聰夫

賢太郎

et al. 2006

Nippon Seramikkusu Kyokai gakujutsu ronbunshi

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Review péÉÅá~ä fëëìÉ Äó dìÉëí bÇáíçêëW lêÖ~åáÅ-íç-fåçêÖ~åáÅ`çåîÉêëáçå mêçÅÉëë Ñçê mçäóãÉê-aÉêáîÉÇ`Éê~ãáÅë pá`_~ëÉÇ`Éê~ãáÅ cáÄÉêë mêÉé~êÉÇ îá~lêÖ~åáÅíçfåçêÖ~åáÅ çåîÉêëáçå mêçÅÉëë-^oÉîáÉï ሱᑿ-ᠪᑿং၁ɟɵɃɁǺȗȚ SiC ṾɃɱɧɋȷέỺǽ۰༔ ἕ◻Several types of Si-based ceramic fibers have been prepared using an organic-to-inorganic conversion process. In this article, the preparation, microstructure, and high-temperature stability of SiC-based ceramic fibers prepared from polycarbosilane of an organosilicon polymer are reviewed. The first fiber produced was an amorphous Si-C-O fiber, next was a low-oxygen content Si-C fiber, and finally, a nearly stoichiometric SiC fiber was developed. These fibers are continuous fine fibers that have high tensile strength with high heat resistance. The pyrolytic behavior and active-passive oxidation of these fibers at high temperatures are described here. The heat resistance of these fibers increases in the order of the Si-C-O fiber, the Si-C fiber, and the SiC fiber. The hightemperature properties are dependent on the atomic arrangement and the quantity of amorphous SiC x O y and glassy carbon in the fibers. Possible applications for these fibers are as refractory materials, and as reinforcement fibers for plastics, metals, and ceramics.

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“…Simultaneously, an increase in the connectivity of S i -C -S i bonds occurs, converting the polymer into an amorphous covalent ceramic (ACC), 33 with a structure that does not vary much from the original PC skeleton. 36 Further pyrolysis to 1300 C C results in the consumption of the free carbon by oxygen present in the fiber, causing the evolution of CO and a substantial reduction in the strength of the fibers. 33 At 1000 °C, ceramic grade Nicalon fibers start forming microcrystallites of SiC.…”

Section: A Nicalonmentioning

confidence: 99%

A comparison of the interphase development and mechanical properties of Nicalon and Tyranno SiC fiber-reinforced ZrTiO₄ matrix composites

Bender

Jessen

1994

J. Mater. Res.

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The differences in interphase development and mechanical properties between Nicalon and Tyranno fiber-reinforced ZrTiO 4 matrix composites were assessed. The composites were reinforced with either uncoated or BN-coated fibers. The microstructure and interphase development were analyzed using scanning electron microscopy, transmission electron microscopy, and analytical electron microscopy. Mechanical behavior was characterized by strength and toughness measurements. Tyranno composites developed thinner interphases due to the differences in the structure and chemistry of the starting fiber resulting from the addition of Ti to the starting polymer precursor. BN-coated fiber composites developed a thicker carbon interphase layer due to incorporation of O into the as-received BN coating. Tyranno composites were weakened by fiber clustering and were not as tough as Nicalon composites due to a lack of thermal debonding.

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Electron probe microanalysis of Nicalon fibres

Cited by 19 publications

References 16 publications

SiC Nicalon fibre-glass matrix composites: interphases and their mechanism of formation

SiC Nicalon fibre-glass matrix composites: interphases and their mechanism of formation

SiC-Based Ceramic Fibers Prepared via Organic-to-Inorganic Conversion Process-A Review

A comparison of the interphase development and mechanical properties of Nicalon and Tyranno SiC fiber-reinforced ZrTiO₄ matrix composites

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Electron probe microanalysis of Nicalon fibres

Cited by 19 publications

References 16 publications

SiC Nicalon fibre-glass matrix composites: interphases and their mechanism of formation

SiC Nicalon fibre-glass matrix composites: interphases and their mechanism of formation

SiC-Based Ceramic Fibers Prepared via Organic-to-Inorganic Conversion Process-A Review

A comparison of the interphase development and mechanical properties of Nicalon and Tyranno SiC fiber-reinforced ZrTiO4 matrix composites

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A comparison of the interphase development and mechanical properties of Nicalon and Tyranno SiC fiber-reinforced ZrTiO₄ matrix composites