Aluminum Carbide

Aluminum carbide, also known as tetraaluminum tricarbide, with the molecular formula Al4C3, is a carbide of aluminum. It is a yellowish brown, hard, transparent rhombohedral crystal, an ionic crystal, non-conductive at room temperature, and has a complex crystal structure. The metal atoms in the structure can be 4, 5, or 6 coordinated, the Al-C bond length is between 1.90 and 2.22 Å, and the shortest C-C bond is 3.16 Å. X-ray studies have shown that there are single carbon atoms in the structure in the form of discrete carbon anions C4−, which is different from acetylene.

Physical and chemical properties：

Density: 2.36g/cm3

Melting point: 2100℃

Appearance: yellow or green-gray crystalline powder

Solubility: insoluble in acetone

Aluminum carbide will hydrolyze when it comes into contact with water.

Al4C3 + 12H2O —→ 4Al(OH)3 + 3CH4

Aluminum carbide is insoluble in propanol.

Biological effects:

Aluminum carbide is toxic and flammable, and releases flammable and explosive gases when in contact with water.

Application:

Aluminum carbide is often used as an additive to enhance the strength of three-component aluminum-based materials (Al-Si-AlC, Al-AlTi-AlC). In addition, Al4C3 is an important compound in the field of aluminum industry technology. It is used to reduce metal oxides in the metallurgical industry, used as a catalyst for chemical reactions in the chemical industry, and used in the ceramic industry to make high-temperature, cutting and mold advanced ceramic materials.

As an ionic compound, in the lattice structure of Al4C3, carbon atoms exist in the form of single C. C has a strong alkalinity and produces methane through C+4H→CH when hydrolyzed, so Al4C3 is also used as a methane generator and desiccant. At the same time, the rhombic hexahedron of AlC is a structure in which Al4C3 and Al4C3 sheets are alternately stacked. It is this unique structure that makes the one-dimensional Al4C3 nanowire a very potential cold electron emitter.