Al4C3

Al4C3, commonly referred to as aluminum carbide, is an inorganic compound with the formula Al4C3. It is a ceramic refractory carbide of aluminum and carbon that forms at high temperatures when aluminum metal reacts with carbon. In some aluminum processing environments, Al4C3 can appear as an undesired byproduct.

Structure and properties: The compound crystallizes as a hard, high-temperature solid with a largely covalent bonding character. It has a very high thermal stability and a high melting point. It is insoluble in water and most acids. It is, however, chemically reactive with moisture, slowly hydrolyzing to form methane and aluminum hydroxide: Al4C3 + 12 H2O → 4 Al(OH)3 + 3 CH4.

Synthesis and occurrence: Al4C3 is prepared by direct combination of aluminum with carbon at elevated temperatures, typically under inert or reducing conditions. It can also form as a byproduct during aluminothermic reductions or carburization processes in which carbon is introduced into molten aluminum.

Applications and implications: In research and materials science, Al4C3 has been investigated as a potential carbiding agent and, in some cases, as a reinforcing phase in aluminum-based composites intended for high-temperature use. Its practical applicability is limited by its instability in the presence of moisture and its tendency to hydrolyze.

Safety and handling: Because it reacts with water to release methane, handling requires protection from moisture and storage under dry, inert conditions.