An intermetallic compound is a solid-state compound that forms between two or more metals (or between a metal and a metalloid) with a defined stoichiometric ratio and a definitive crystalline structure. These compounds often exhibit unique mechanical properties, thermal properties, and chemical properties compared to the original metals.

Key Features:

• Ordered Nature of the Crystal: Atoms are positioned in a fixed, repeatable manner and contribute to high strength.
• High Hardness & Brittleness: Generally harder and more brittle than conventional alloys.
• Good Thermal Stability: Will perform at elevated temperatures.

Intermetallic compounds are used for applications that require high strength-to-weight ratios, corrosion resistance, or heat resistance, such as jet engines, turbine blades, and electronic components. For example, NiAl (nickel-aluminum) and TiAl (titanium-aluminum) were highly sought after by the aerospace industry, as they are lightweight, passable temperature resistors, and the emergence of titanium aluminides for jet engines, but are limited by low ductility, complications in processing, and requiring control in design and manufacturing. Research continues to improve toughness and workability to expand the use of intermetallic into structural and functional materials.