Boron nitride composites

Before that time, experimental evidence for the existence of heterofullerenes was very rare. In 1991 Smalley and co-workers [4,5] reported on the mass spectrometric detection of borafullerenes C5q B (n = 1-6) generated by laser vaporization of graphite-boron nitride composites. Later, in the same year, the preparation of several clusters was reported [6-8]. However, none of these species has been isolated or structurally characterized. In 1994 Clemmer et al. presented evidence for heterofullerenes containing a metal as part of the framework [9]. Muhr etal. reported on the preparation of monoborafullerenes however, presumably due to the instability of these systems, no pure material could be isolated and completely characterized [10]. Real preparative heterofullerene chemistry began in 1995. The... 

Key words silicon nitride boron nitride composite ceramics pressureless sintering ... 

Harrison, C., S. Weaver, C. Bertelsen, E. Burgett, N. Hertel, and E. Grulke. 2008. Polyethylene/boron nitride composites for space radiation shielding. J. Appl. Polym. Sci. 109 2529-2538. 

Table 7.12 The results of photocatalytic hydrogen generation from hydrazine solution in the presence of Fe-containing boron nitride composites (CN2H4 = 9-1 H2O2 3.75-10" M ...

H. R. Frank and D. S. Phillip, Enhanced Boron Nitride Composition and Polymer Based High Thermal Conductivity Molding Compound, EP 0 794 227 B1 (2002). 

H. Ishida, Surface Treated Boron Nitride for Forming A Low Viscosity High Thermal Conductivity Polymer Based on Boron Nitride Composition and Method, US Patent, 6,160,042 (2000). 

The different types of boron nitride composites cited can be reinforced with fibrous materials such as titanium alloy fibers [287], Si/Zr oxynitride fibers [288], SiOg/TiOg/ZrOg fibers [289], and carbon fibers [290 to 292, 313] (see also Section 4.1.1.10.1, p. 58). BN-containing oxide and carbide ceramics are used to protect graphite from being attacked in metallurgical processes [293 to 295]. Porous ceramics and ceramic foams which can be infiltrated either with metals or lubricants may contain a-BN or are produced in boron nitride ceramic molds [296 to 299]. 

Morris, J. R. and Tanzilli, R. A. (1987) Aluminum Nitride-Boron Nitride Composite Article and Method of Making Same, U.S. Pat. 4666,873. 

Figure 19s Microstructure of reaction processed (twllite - 30 volX boron nitride composite.

Pierson, H.O., Boron Nitride Composites by Chemical Vapor Deposition. J. Composite Materials 9 228-239 (1975). 

THERMAL PROPERTIES AND STRUCTURE OF INJECTION MOLDED THIN-WALL PRODUCTS OF POLYPROPYLENE/BORON-NITRIDE COMPOSITES... 

Key words thin-wall injection molding. Boron nitride, composites, thermal conductivity... 

Cera.micA.bla.tors, Several types of subliming or melting ceramic ablators have been used or considered for use in dielectric appHcations particularly with quartz or boron nitride [10043-11 -5] fiber reinforcements to form a nonconductive char. Fused siHca is available in both nonporous (optically transparent) and porous (sHp cast) forms. Ford Aerospace manufactures a 3D siHca-fiber-reinforced composite densified with coUoidal siHca (37). The material, designated AS-3DX, demonstrates improved mechanical toughness compared to monolithic ceramics. Other dielectric ceramic composites have been used with performance improvements over monolithic ceramics (see COMPOSITE MATERIALS, CERAMIC MATRIX). 

Fig. 16. Insulator wall designs (a) peg wall (b) conducting bar wall and (c) segmented bar wall. The gas-side materials are tungsten and tungsten—copper composite, the base material, copper, and the insulators, boron nitride. Slagging grooves are shown.

Development of practical and low cost separators has been an active area of ceU development. CeU separators must be compatible with molten lithium, restricting the choice to ceramic materials. Early work employed boron nitride [10043-11-5] BN, but a more desirable separator has been developed using magnesium oxide [1309-48-4], MgO, or a composite ofMgO powder—BN fibers. Corrosion studies have shown that low carbon steel or... 

Saitoh, H., Yoshida, K., and Yarborough, W., Crystal Structure of New Composition Boron Rich Boron Nitride Using Raman Spectroscopy, J. Mater. Res., 8(1) 8-11 (Jan. 1993)... 

C. Zhi, Y. Bando, T. Terao, C. Tang, H. Kuwahara, D. Golberg, Towards thermoconductive, electrically insulating polymeric composites with boron nitride nanotubes as fillers, Adv. Fund. Mater, vol. 19, p. 1857-1862, 2009. 

Naslain, R., Dugne, O., Guette, A, Sevely, J., Robin-Brosse, C.R., Rocher, J.P. and Cotteret, J. (1991a). Boron nitride interphase in ceramic-matrix composites, J. Am. Ceram. Soc. 74, 205-214. 

Ryder, C.. Vidoz, A., Crossman, F., Camahorl, J. (1970), Mechanical properties of nitrided boron-aluminium composites, J. Composite Mater. 4, 264-272. 

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