Ceramics are objects made of materials that are permanently hardened by being heated. Usually, the word is used to mean articles made of various forms of clay. Sticky clay is dug from the Earth and needs to have impurities, such as stones, removed before it can be used. The clay may be naturally red, yellow, grey or almost white, but can be coloured before shaping or covered with a coloured glaze.
Ceramics are essential for our day to day life. It is useful from clay products to porcelain. Generally, a ceramic is a non-metallic, solid inorganic compound. Earlier ceramics were used only for pottery. Now, with the changing times, ceramics are more and more used only for specific purposes. Use of ceramics has been from ancient times. Based on these uses there are three basic types of ceramics:
Stoneware
Stoneware is an umbrella term for ceramics fired at a higher temperature. It is known for being impermeable and hard so it’s not easily scratched. It is typically glazed. Modern brands such as Far & Away have really brought this type of ceramic back into the mix.
Clay products
In this category, many of the common ceramics like bricks and tiles are used. They are basically prepared from clay. For their shape and state, they are processed and pressed in a wet plastic state after which they are dried and then fried. Clay products that have higher density show better mechanical properties but they also have the low insulating capacity. And thus can easily catch fire. Higher density is achieved through an increase in nitrifications and also through increasing fire temperature and finer original particle size.
Refractories
Ceramic can resist higher temperatures and that is why they are also used as refractories. Refractor ceramics can withstand very high temperature and are thus used as insulating materials. They can also resist high stress. Refractors should also resist abrasive particles, hot gasses, and molten metals. For best refractors ceramics made of pure oxide is used. But these are very expensive and thus compounds made out of ceramics are used more often.
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