Boron nitride coatings composites

Method b, the so-called hot pressing method is suitable for making dense composites. A 2D woven Hi-Nicolon tissue with or without a boron nitride coating (BN) is used as reinforcement. All of this is illustrated by the following photographs. 

Sun, E.Y., S.R. Nutt, and J.J. Brennan. 1996. High temperature tensile behavior of a boron nitride-coated silicon carbide-fiber glass-ceramic composite. Journal of the American Ceramic Society 79 1521-1529. ... 

Multi-component ceramics allow the optimization of various physical properties. These include ceramics which form multi-component oxides as well as fiher-rein-forced ceramic matrix composites. However, the oxidation behavior of these materials is complex compared with the pure materials. The leading fiber-reinforced composites are silicon-based and contain continuous SiC fibers with coatings of graphitic carbon or hexagonal boron nitride. The oxidation of the fiber coating at intermediate temperatures is a major issue and models of this process are discussed for both carbon and boron nitride coatings. 

Wider use of fiber-reinforced ceramic matrix composites for high temperature structural applications is hindered by several factors including (1) absence of a low cost, thermally stable fiber, (2) decrease in toughness caused by oxidation of the commonly used carbon and boron nitride fiber-matrix interface coatings, and (3) composite fabrication (consolidation) processes that are expensive or degrade the fiber. This chapter addresses how these shortcomings may be overcome by CVD and chemical vapor infiltration (CVI). Much of this chapter is based on recent experimental research at Georgia Tech. 

S. T. Gonczy, E. P. Butler, N. R. Khasgiwale, L. Tsakalakos, W. R. Cannon, and S. C. Danforth, Blackglas-Nicalon composites with CVD boron nitride fiber interface coatings,... 

Chem. Descrip. Boron nitride CAS 10043-11-5 EINECS/ELINCS 233-136-6 Uses Lubricant, filler for elec, insulating/thermally conductive materials, polymer matrixes, adhesives, pastes, potting compds., EP lubricants, refractories, refractory coatings, mold/die release, metal/ceramic and ceramic/matrix composites... 

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