Aluminum carbide

Aluminum carbide is an inorganic binary compound of carbon with aluminum. Its chemical formula is written as Al4C3, it looks like a pale yellow or brown crystal with a complex structural lattice. It is able to withstand a temperature rise up to 1400 ° C at a density of 2.36 g / cm³. As part of its lattice, carbon atoms are present as discrete carbon anions. This compound is obtained by direct reaction of carbon with aluminum in an arc furnace, and also its insignificant amount is present in impurities of calcium carbide of technical origin.

Aluminum carbide : characteristics and application

Electrolytic aluminum production implies the isolation of this compound as a corrosive product in graphite electrodes. In the case where aluminum carbide reacts with water or a dilute acid, methane is formed. In addition, the compound reacts with oxygen and hydrogen, and in the case of reaction with water and a sodium hydroxide concentrate, a complex salt is formed called tetrahydroxoaluminate of methane and sodium. Naturally, the compound has specific physical properties, this refers to the refractive indices related to the sodium D-line and reaching 20 ° C. At the same time, standard Gibbs energy and standard entropy of formation are taken into account, these parameters reach 196 and 88.95 J / mol / K. The preparation of this compound is possible as an undesirable product in complex chemical reactions.

In particular, metal matrix connections based on an aluminum matrix and reinforced with metallic carbides, such as boron carbide and silicon carbide, can contribute to the occurrence of aluminum carbide as an unwanted element. A similar situation is possible in the case of carbonaceous fiber, which upon reaction with an aluminum matrix at temperatures above 500 ° C also separates the compound under consideration. During the passage of a chemical reaction between cast aluminum and silicon carbide, an aluminum carbide layer can form, it will cover silicon carbide particles and reduce the strength of the material.

However, this effect can be reduced by coating the silicon particles with a suitable oxide or pre-oxidizing them to form a quartz coating. To determine how much tritium is contained in the water, the compound is hydrolyzed, resulting in aluminum carbide methane. In this case, the compound is used as a chemical reagent, a tritium and methane compound is produced by reaction with suspended water. Aluminum carbide, scattered through an aluminum matrix, helps maintain the density of the material, especially if it is combined with silicon carbide particles.

Composite materials from aluminum carbide can be obtained thanks to mechanical alloys based on aluminum powder and graphite particles. Together with this, the compound is used as an abrasive for cutting high-speed tools, giving them the hardness of topaz. Another area of application of the compound is pyrotechnics, here it allows you to get a firefly effect, which is expressed in the excess appearance of sparks. Note that at various times in pyrotechnics, it has always been used with varying intensity. In general, this compound is widely used in the chemical industry and manufacturing. This is due to the chemical characteristics of aluminum carbide, providing its unique properties, not characteristic of other types of compounds of the carbide group.