Process ceramic fibers by Sol-Gel
The Sol-Gel process may transform the materials of construction chemical engineers make and use--thin films, fibers, and powders. The advantage of the Sol-Gel technology is the ability to produce high purity products at low temperatures. For example, silica film is used to passivate integrated circuits. To achieve this, the native silicon substrate now is oxidized at about 1,000C for a short period of time. At this temperature, diffusion of the dopant atoms may be induced to alter the electronic properties of the chip. In contrast, the film application using Sol-Gel may be done at 400-600C. Another example is the interest in ceramic fibers to incorporate in fiber-reinforced ceramic matrix composite materials. The latter is considered an enabling technology for the 21st Century high-speed civil transport plane (NASA) and the National Aerospace plane (X-30). Glass and ceramic fibers have been prepared conventionally by drawing or blowing a high temperature melt through an orifice. The traditional process requires the conversion of the raw materials into a homogeneous, high temperature melt, which makes producing fibers based on materials having high melting points or materials that are immiscible in the liquid state difficult. The Sol-Gel process applied to the production of fibers offers an advantage over the conventional method, since the fibers are drawn from the Gel at low temperatures and then are converted to glass or ceramics by heating the fibers at high temperatures, T[lt]600C. Also by using this technique there is the potential to produce glasses of new compositions with high purity and homogeneity. This article will briefly discuss the polymerization aspect of the Sol-Gel process. The chemical, physical, and rheological aspects of the process to produce the desired product will be discussed.
- OSTI ID:
- 5653018
- Journal Information:
- Chemical Engineering Progress; (United States), Journal Name: Chemical Engineering Progress; (United States) Vol. 89:9; ISSN 0360-7275; ISSN CEPRA8
- Country of Publication:
- United States
- Language:
- English
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Sol-gel processes and materials. (Latest citations from the Aerospace database). Published Search
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