Aluminum carbide is an inorganicbinary compounds of carbon with aluminum. Its chemical formula is written as Al4C3, it looks like a pale yellow or brown crystal, which has 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 productionimplies the isolation of this compound as a corrosive product in graphite electrodes. In the case where aluminum carbide reacts with water or dilute acid, methane is formed. In addition, the compound reacts with oxygen and hydrogen, and in the case of interaction 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, in metal matrixjoints based on an aluminum matrix and reinforced with metal carbides, such as boron carbide and silicon carbide, can contribute to the occurrence of aluminum carbide as an undesirable element. A similar situation is possible in the case of carbonaceous fiber, which upon reaction with a matrix of aluminum at temperatures above 500 ° C also releases the compound in question. During the passage of the 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 reducedby coating the silicon particles with a suitable oxide or pre-oxidizing them to form a quartz coating. To determine how much tritium is in the water, the compound is hydrolyzed, resulting in aluminum carbide methane. In this case, the compound is used as a chemical reagent, a reaction with suspended water produces a tritium-methane compound. 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 carbidecan 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 connection is pyrotechnics, here it allows you to get the effect of a firefly, which is expressed in the excessive appearance of sparks. Note that at different 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.
