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:
1. Clay products
3. Industrially used ceramics
1. 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 vitrification and also through increasing fire temperature and finer original particle size.
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.
3. Industrially used ceramics:
Ceramics are abrasive in nature, can withstand electrical shocks and are also magnetic in nature. And that is why ceramics are also used for industrial purposes. They can perform a variety of electrical and magnetic operations. Some ceramics like graphite are good conductors while others like SiC have a high resistivity which can also be used in heating materials. Conductivity in ceramics increases along with the temperature because it is based on anions and cations. These movements are only possible when there is a sufficient thermal energy to supply.
Ceramics possess two types of magnetic categories- low conductivity and superconducting magnets. Low conductivity is used in transformers like objects where a magnet is also required to have some electrical properties. Ceramics has a special property of conducting electricity without resistance and so no energy loss. This property can be useful for superconducting magnets. As this is only possible at a critical temperature and magnetic field this property is very limited.
Ceramics are also abrasive in nature. These type of ceramics are used to grind and cut the softer materials. The abrasive material is also hard in nature and can wear resistance which is a very important property for its design. Along with this toughness is also required as they do not get shatter while grinding. Abrasives can be natural or synthetic. Some of the examples we can see in day to day life are silicon carbide, normal silica sand, and tungsten carbide.