Structure Of Ceramic Materials

Thus in order to fully understand the properties of ceramics a knowledge of their structure is essential.

Structure of ceramic materials.

A common definition of a ceramic is a hard material that is held together with ionic and covalent bonds. Compare to other materials ceramics have some unique properties. 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. The two most common chemical bonds for ceramic materials are covalent and ionic.

Additionally carbon based materials such as carbon fiber carbon nanotubes and graphene can be considered ceramics. Sometimes even monocrystalline materials such as diamond and sapphire are erroneously included under the term ceramics. 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. Graphene is currently considered the strongest known material.

Ceramics are oxides carbides nitrides borides of metal ions. The properties of ceramics however also depend on their microstructure. All ceramic materials are prepared by ceramic technology and powder substances are used as the initial raw materials. The bonding of atoms together is much stronger in covalent and ionic bonding than in metallic.

Ceramics are compounds of metallic elements and non metallic substances such as oxides nitrides and silicates. 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. Structural ceramics are typically manufactured by a variety of techniques including injection molding uniaxial hot pressing compression molding slip casting and sintering. In atomic structure they are most often crystalline although they also may contain a combination of glassy and crystalline phases.

For example alumina al2o3 is a compound made up of aluminum atoms and oxygen atoms. Ceramic materials like clay are categorized as traditional ceramics and normally they are made of clay silica and feldspar. According to this definition elemental carbon is a ceramic. Ceramics play an important role in our day to day life.

Most ceramics are made up of two or more elements. Their physical properties are an expression not only of their composition but primarily of their structure. Polycrystalline materials are formed by multiple crystal grains joined together during the production process whereas monocrystalline materials are grown as one three dimensional crystal. Ceramics are by definition natural or synthetic inorganic non metallic polycrystalline materials.

In ceramics the negatively charged ions anions are often significantly different in size from the positively charged ions cations. This is called a compound. Generally they are inorganic and non metallic.