Structure Of Ceramic Materials

The properties of ceramics however also depend on their microstructure.

Structure of ceramic materials.

Ceramics are compounds of metallic elements and non metallic substances such as oxides nitrides and silicates. This is called a compound. The bonding of atoms together is much stronger in covalent and ionic bonding than in metallic. As its name suggests traditional ceramics are not supposed to meet rigid specific properties after their production so cheap technologies are utilized for most of the production processes.

Additionally carbon based materials such as carbon fiber carbon nanotubes and graphene can be considered ceramics. Polycrystalline materials are formed by multiple crystal grains joined together during the production process whereas monocrystalline materials are grown as one three dimensional crystal. Their physical properties are an expression not only of their composition but primarily of their structure. Concise encyclopedia of advanced ceramic materials 1991.

A common definition of a ceramic is a hard material that is held together with ionic and covalent bonds. Usually they are metal oxides that is compounds of metallic elements and oxygen but many ceramics especially advanced ceramics are compounds of metallic elements and carbon nitrogen or sulfur. Ceramics play an important role in our day to day life. All ceramic materials are prepared by ceramic technology and powder substances are used as the initial raw materials.

For example alumina al2o3 is a compound made up of aluminum atoms and oxygen atoms. In ceramics the negatively charged ions anions are often significantly different in size from the positively charged ions cations. Graphene is currently considered the strongest known material. In atomic structure they are most often crystalline although they also may contain a combination of glassy and crystalline phases.

Ceramics generally start with a clay based material dug from the ground that s mixed with water to make it soft and flexible and other materials squashed into shape then fired at high temperature in a large industrial oven called a kiln. Sometimes even monocrystalline materials such as diamond and sapphire are erroneously included under the term ceramics. Ceramics are by definition natural or synthetic inorganic non metallic polycrystalline materials. Generally they are inorganic and non metallic.

Ceramics can appear as either crystalline or amorphous solids the latter group being called glasses. Development of ceramics helps to decrease the demand in industries. According to this definition elemental carbon is a ceramic. Ceramics are oxides carbides nitrides borides of metal ions.

Most ceramics are made up of two or more elements. The two most common chemical bonds for ceramic materials are covalent and ionic. Thus in order to fully understand the properties of ceramics a knowledge of their structure is essential.