Borosilicate/carbon composites

Boron monofilaments (about 20 vol.%) were used by Tredway and Prewo to reinforce borosilicate glass [84]. They also introduced carbon fibre yarn to fill in the glass-rich regions between monofilaments in order to toughen the matrix and provide additional structural integrity of the composite. 

A. R. Boccaccini, D. B. Acevedo, G. Brusatin, and P. Colombo, Borosilicate glass matrix composites containing multi-wall carbon nanotubes, J. Europ. Ceram. Soc. (2004) in press. 

The interface between HM carbon fiber and a Pyrex borosilicate glass matrix was Analyzed by Bleay and Scott [111,112] and found to be some 100 nm thick and believed to comprise Na enriched silicon oxycarbide, showing that some reaction had taken place during fabrication. Measurement of the interlaminar shear strength of the composite indicated that this layer was not a source of weakness. Substantial fiber pull-out had occurred, however, exposing clean fiber surfaces and smooth sockets. It was concluded that the interfacial shear process was confined to the outer layer of the fiber. Heat treatment of the composite in air caused preferential oxidation of the fiber, the rate being higher parallel to the fiber axis than perpendicular to it. 

Crosbie GM, Nicholson JM, Deering LA, Pseudo 3-D reinforcement with stretch-broken carbon fibers in a borosilicate glass matrix, JP Singh, Bansal NP eds.. Advances in Ceramic-Matrix Composites II, Ceram Trans, American Ceramic Soc Inc, Indianapolis, 46, 211-222, Apr 25-27 1994. 

Kaya C, Boccaccini AR, Chawla KK, Electrophoretic deposition forming of Ni-coated carbon fibre reinforced borosilicate glass matrix composites, J Am Ceramic Soc, 83, 1885, 2000. 

Materials used in the preparation of buffer solutions should be good quality laboratory chemicals, purified if necessary as described in Chapter 8 and dried to constant composition. The distilled water used as solvent should have been recently boiled to remove dissolved carbon dioxide and have been protected from contamination by atmospheric carbon dioxide while cooling. (This precaution is unnecessary in preparing buffer solutions having pH values less than 5.) The water should have a specific conductivity of less than 2 X 10 ohm cm at 25°C. Solutions should be stored in stoppered Pyrex (or similar borosilicate glass) or pure polyethylene bottles. 

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