Structure Of Metal And Ceramics

The two most common chemical bonds for ceramic materials are covalent and ionic.

Structure of metal and ceramics.

Charge balances and relative ion size plays key roles in determining structure and properties. For metals the chemical bond is called the metallic bond. The bonding of atoms together is much stronger in covalent and ionic bonding than in metallic. Depending on the physical structure of the material cermets can also be metal matrix.

The atoms in ceramic materials are held together by a chemical bond. 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. Therefore the structure the metallic atoms the structure of the nonmetallic atoms and the balance of charges produced by the valence electrons must be considered. In atomic structure they are most often crystalline although they also may contain a combination of glassy and crystalline phases.

Sometimes even monocrystalline materials such as diamond and sapphire are erroneously included under the term ceramics. Most ceramics usually contain both metallic and nonmetallic elements with ionic or covalent bonds. Bonding ranges from ionic to covalent. Ceramics are by definition natural or synthetic inorganic non metallic polycrystalline materials.

A cermet is a composite material composed of ceramic and metal materials. Polycrystalline materials are formed by multiple crystal grains joined together during the production process whereas monocrystalline materials are grown as one three dimensional crystal. Generally the metallic elements used are nickel molybdenum and cobalt. The metal is used as a binder for an oxide boride or carbide.