Engineering Science 1021A/B Lecture Notes - Lecture 25: Formability, Stoneware, Corel
17 May 2018
School
Department
Professor
Ceramic-glasses have a combination of crystalline and glassy components
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Combination of crystalline and glass phases in their microstructure
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Porcelain, China, Bricks
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Fabricating Glass-Ceramics
Powders of a crystalline ceramic and clay are mixed with water and formed into
“green” shapes
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Increasing the water content increases the formability of the powders
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Green bodies are first dried to remove the water and then fired to vitrify the
clay (turn it to glass)
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The higher the firing temperature, the more complete the vitrification and the
lower the porosity
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Earthenware (pottery): has a relatively low firing temperature and is quite
porous – therefore a glaze is required
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Stoneware: higher temperature, used for sewer and drainage pipe
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China and porcelain: even higher temps, no porosity
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Corel
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Properties
Hard
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Brittle
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Corrosion resistant
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Some porosity, but can be minimized by increasing the firing temperature•
High temperature creep properties are better than glasses but not good as
crystalline ceramics
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Glass-Ceramics
