Interfacial reactions between a lead borosilicate glass dielectric coating and an Al/SiC metal matrix composite
UNSPECIFIED (2000) Interfacial reactions between a lead borosilicate glass dielectric coating and an Al/SiC metal matrix composite. In: 3rd International Conference on Borate Glasses, Crystals and Melts, JUL 04-09, 2000, SOFIA, BULGARIA.Full text not available from this repository.
A PbO rich borosilicate glass has been developed as a thick film, dielectric coating for an AllSiC particle reinforced metal matrix composite (MMC). Sessile drop experiments were performed to investigate interfacial reactions The wetting behaviour of the glass, highly fluid at the bonding temperature (500-600 degreesC), was found to be a function of atmosphere, temperature and time. Coatings applied under air exhibited similar to 10% porosity attributed to the production of CO2 gas through the oxidation of SiC at the glass/MMC interface This may occur via oxygen diffusion through the glass drop from the air to the interface or via a redox reaction between the SiC and the lead oxide component of the glass at the glass/ MMC interface, the fatter generating free lead metal as a waste product. The lack of lead metal precipitates in the air bonded coatings indicates that, if the redox route is occurring, oxygen may diffuse through the glass to reoxidise the free lead produced maintaining the original glass composition. Under inert atmosphere, redox reactions remove large quantities of lead from the glass, modifying the glass composition to a borosilicate and precipitating lead metal. The cause of the extensive porosity in shorter hold time coatings needs further investigation, although the effect may be due to the trapping of CO2 gas in the glass matrix through increased glass viscosity. Coatings on pure Al, free of SiC, exhibited near zero porosity and negligible free lead precipitation in all atmospheres verifying the SiC redox theory.
|Item Type:||Conference Item (UNSPECIFIED)|
|Subjects:||Q Science > QD Chemistry
T Technology > TP Chemical technology
|Journal or Publication Title:||PHYSICS AND CHEMISTRY OF GLASSES|
|Publisher:||SOC GLASS TECHNOLOGY|
|Number of Pages:||5|
|Page Range:||pp. 267-271|
|Title of Event:||3rd International Conference on Borate Glasses, Crystals and Melts|
|Location of Event:||SOFIA, BULGARIA|
|Date(s) of Event:||JUL 04-09, 2000|
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