Structure Of Metal And Ceramics

The metal is used as a binder for an oxide boride or carbide.

Structure of metal and ceramics.

The bonding of atoms together is much stronger in covalent and ionic bonding than in metallic. Ceramic crystal structures generally more complex than metals because they are composed of at least two elements or more. 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. Polycrystalline materials are formed by multiple crystal grains joined together during the production process whereas monocrystalline materials are grown as one three dimensional crystal.

The two most common chemical bonds for ceramic materials are covalent and ionic. For metals the chemical bond is called the metallic bond. In atomic structure they are most often crystalline although they also may contain a combination of glassy and crystalline phases. The atoms in ceramic materials are held together by a chemical bond.

The properties of ceramics however also depend on their microstructure. Sometimes even monocrystalline materials such as diamond and sapphire are erroneously included under the term ceramics. Charge balances and relative ion size plays key roles in determining structure and properties. 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.

Generally the metallic elements used are nickel molybdenum and cobalt. A cermet is ideally designed to have the optimal properties of both a ceramic such as high temperature resistance and hardness and those of a metal such as the ability to undergo plastic deformation. Ceramics are by definition natural or synthetic inorganic non metallic polycrystalline materials. Most ceramics usually contain both metallic and nonmetallic elements with ionic or covalent bonds.