Nicalon fibre

The Nicalon fibre (10-20 pm) available commercially consists of a mixture of P-SiC free carbon and Si02 [28], The properties of Nicalon start to degrade above about 600°C because of the thermodynamic instability of the composition and microstructure. Ceramic-grade Nicalon fibres, designated the NL series, having low oxygen content are also available. 

Chyung, K., etal., Nicalon fibre reinforced LAS glass-ceramic composites , presented at the 9th Conf. on Composite Materials, January 1985, Cocoa Beach, FL. 

CMCs with 2-D woven fibre reinforcements have been found to possess higher resistance to thermal shock than unidirectional or cross-ply CMCs of the same constituents (Nicalon fibres and SiC matrices) and prepared by the same method (Chemical Vapour Infiltration-CVI) (Wang et al., 1997). 

Reprinted from J. Eur. Ceram. Soc., 21(5), Demir A and Thompson D P, High-performance SiC-fibre reinforced fi-sialon CMCs prepared from heat-treated Nicalon fibres, 639-647 (2001). Copyright 2001, with permission of Elsevier. 

Bibbo, G.S., Benson, P.M. and Pantano, C.G., (1991), Effect of carbon monoxide partial pressure on the high-temperature decomposition of Nicalon fibre , J. Mater. Sci., 26(18), 5075-5080. 

Non planner laminates were also fabricated using Nicalon fibres as a depositing... 

The polymer is heated until molten, forced through an appropriately sized aperture, and solidified as it is drawn into a fibre the commercial process produces multifilament fibres rather than single strands and cross-linking of the filaments adds strength to the final product. The composition of Nicalon fibres is not as simple as this description implies carbon and silica are present in addition to P-SiC. 

FIGURE 2. TEM micrograph showing the interfacial zone in a SiC-Nicalon fibre-reinforced borosilicate glass matrix composite. The carbonaceous interface is clearly observed. (Micrograph reproduced with permission from Ref. [6]). 

FIGURE 6. A typical microstructure of a borosilicate glass matrix composite reinforced with unidirectional SiC-Nicalon fibres (40 vol%) fabricated by hot-pressing (Schott Glas, Mainz, Germany). The micro structure is characterised by the absence of porosity and a fairly homogenous distribution of the fibres [6]. 

FIGURE 10. A typical fracture surface of a borosilicate glass matrix composite reinforced by Nicalon fibres... 

The erosion resistance of carbon and SiC (Nicalon ) fibre-reinforced composites has been studied using an erosive jet of sand and other solid particles at both room and elevated temperatures (up to 750 C) [21, 145]. At temperatures above about 5(X)°C oxidation of the carbonaceous interface and subsequent development of silica bridges should occur, which has a significant detrimental effect on erosion behaviour. The development of oxide... 

P. N. Kumta, Processing Aspects of Glass-Nicalon Fibre and Interconnected Porous Aluminium Nitride Ceramic and Glass Composites, J. Mat. Sci. 31, 6229-6240 (1996). 

E. Y. Sun, S. R. Nutt and J. J. Brennan, Interfacial Microstructrrre and Chemistry of SiC/BN Dttal Coated Nicalon Fibre Reinforced Glass-Ceramic Matrix Composites, J. Am. Ceram. Soc. 77, 1329-1339 (1994). 

S. M. Bleay, V. D. Scott, B. Harris, R. G. Cooke and F. A. Habib, Interface Characterization and Fracture of Calciinn Aluminosihcate Glass-Ceramic Reinforced with Nicalon Fibres, 7. Mat. Sci. 27, 2811-2822(1992). 

N. P. Bansal and J. I. Eldrige, Hi-Nicalon Fibre-Reinforced Celsian Matrix Composites Influence of Interface Modification, /. Mat. Res. 13, 153(L1537 (1998). 

K. Chyimg and S. B. Dawes, Fhioromica Coated Nicalon Fibre Reinforced Glass-Ceramic Composites, Mat. Sci. Eng. A162, 27 33 (1993). 

A. Hahnel, E. Pippel and J. Woltersdorf, Nanostructure of Interlayers in Different Nicalon Fibre/Glass Matrix Composites and their Effect on Mechanical Properties, J. Microscopy 177, 264-271 (1995). 

FIGURE 10. Hybrid barium magnesium aluminosilicate glass-ceramic matrix composite with Nicalon fibre and SiC-whisker reinforcement. The white dots are SiC whiskers distributed in the glass-ceramic matrix. (Micrograph courtesy of Prof. K. Chawla, University of Alabama at Birmingham, USA). 

Hybrid aluminosilicate glass matrix composite with Nicalon fibre and SiC particulate reinforcement Fracture strength 778 MPa-827 MPa (depending of SiC particulate content) High-lemperature aerospace applications [74]... 

C. Valhas. P. Rocabois and C. Bernard, Thermal degradation mechanisms of Nicalon fibre a thermodynamic simulation, J. Mater. Sd., 29,5839-46 (1994). 

The precursor polymer developed by Yajima to produce the first SiC-based fibres was a polycarbosilane (PCS) which can be simplified as -(SiCHjH-CHaJn-. The average molecular weight was adjusted to be around 1500 (Yajima et al., 1978) to enable the polymer to be spun from the melt. The industrial application of this polymer for the fabrication of fibres allowed the fabrication in an industrial scale of the first Nicalon fibres in 1983 by Nippon Carbon. These fibres were the Nicalon 100 series which were superseded by the 200 series. 

The structure of the Hi-Nicalon fibre can be represented as being composed of about 59% of P-SiC by weight, 11% of free carbon and the 26% of non-crystallised Si-C combined with the 4% of Si-C-O phase described above, giving 30% of an intergranular phase composed in majority of SiC with some substitution of carbon by oxygen. As with the NL 200 fibre the Hi-Nicalon contains a small amount of nanometric porosity. 

The Tyranno LOX-E fibre was produced by Ube Industries by the electron radiation method adopted by Nippon Carbon for the Hi-Nicalon fibre. However, the introduction... 

Fig. 4. The micro-struclure of the Hi-Nicalon fibre is composed of SiC grains of 5 nm average si/e and free carbon.

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