Intermetallic materials

Intermetallic are materials with an ordered arrangement of mixed atom sorts of metal-metal or metal semimetal types, generally in a near stoichiometric composition. There are several intermetallic composites, which are used in the industries , the main groups within which they can be classified are:nickel aluminides, iron aluminides, titanium aluminides and others such as silicides, nickel titanium, and refractory metal. Aluminides are especially interesting because for most of them, their ordering temperature is close to the melting temperature.

Intermetallic compounds have a particular chemical formula with a fixed or narrow range of chemical composition. In addition, instead of their atoms being linked with relatively weak metallic bonds, the bonding may be partly ionic or covalent, which gives them an ordered crystal lattice. Some intermetallics can even keep this order until their melting point, which is the main reason. why they possess strong stability at high temperatures.

The main properties of intermetallics can be summarized as follows: high melting points; high thermal conductivity; low densities; great strength, particularly at high temperatures; good oxidation resistance at high temperatures (because of the formation of oxide films); low ductility; brittle fracture at room temperature; low creep resistance and processing problems .

The most important intermetallic compounds and some their properties are summarized in table1

Table1: important intermetallic