Aluminum boride (AlB2) is a binary compound formed by aluminum and boron, at room temperature and atmospheric pressure for gray red solid, heating to lose the surface luster, stable in cold dilute acid, hot hydrochloric acid and nitric acid decomposition, by aluminum and boron fine powder mixed after heating reaction, it is one of the two compounds of aluminum and boron, the other is AlB12, They are commonly referred to as aluminum boride. AlB12 is a black glossy monoclinic crystal, specific gravity 2.55(18℃), insoluble in water, acid, alkali, decomposition in hot nitric acid, from boron trioxide, sulfur, aluminum melting together. Structurally, the B atoms form graphite-like sheets with Al atoms between them, which is very similar to the structure of magnesium diboride. The single crystals of AlB2 exhibit metallic conductivity on axes parallel to the hexagonal plane of the base. Boron - aluminum composite materials with boron fiber or protective coating boron fiber reinforced aluminum or aluminum alloy, boron fiber volume content is generally about 45% to 55%. Low specific gravity, high mechanical properties. The longitudinal tensile strength of the unidirectional reinforced boron-Al composite is about 1.2~1.7GPa, and the elastic modulus is about 200~240GPa. The longitudinal specific elastic modulus and specific strength are about 3~5 times and 3~4 times of titanium alloy aluminum and alloy steel, respectively. Good fatigue performance, below 400℃ still has a high strength, has been used in turbojet engine fan blades and aviation, aerospace vehicles and artificial satellite structural parts. The hot pressing and diffusion bonding method is used to manufacture plates, profiles and parts with more complex shapes. Various profiles can also be manufactured using the continuous casting method.
Production method:
The structure of aluminum boride is similar to that of metal intercompounds, and its structure mainly depends on the crystal structure of aluminum metal and boron rather than on their valence relationship. Aluminium borides are AlB2, AlB4 and AlB12. The diboride AlB2 can be formed by the reaction of two elements above 600℃. It is A layered structure, with Al atoms directly overlapping (A, A mode), and B atoms filled in the triangular column formed by the direct overlapping of Al atoms, that is, the boron layer is between the two aluminum layers. The boron layer is similar to the graphite structure, with boron atoms connected in a hexagonal network, each B atom is 0.173nm away from the other three B atoms, and there are six Al atoms connected with B, which occupy the vertices of the triangular column. AlB2 can be dissolved in dilute hydrochloric acid to produce a reductive solution that may contain HB(OH)+3. AlB2 is insoluble in dilute sulfuric acid, but soluble in nitric acid. AlB2 decomposes to form AlB12 above 920℃.
Product performance
The structure of aluminum boride is similar to that of metal intercompounds, and its structure mainly depends on the crystal structure of aluminum metal and boron rather than on their valence relationship. Aluminium borides are AlB2, AlB4 and AlB12. The diboride AlB2 can be formed by the reaction of two elements above 600℃. It is A layered structure, with Al atoms directly overlapping (A, A mode), and B atoms filled in a triangular column formed by direct overlapping Al atoms, that is, the boron layer is between two aluminum layers. The boron layer is similar to the graphite structure, with boron atoms connected in a hexagonal network, each B atom is 0.173nm away from the other three B atoms, and there are six Al atoms connected with B, which occupy the vertices of the triangular column. AlB2 can be dissolved in dilute hydrochloric acid to produce a reductive solution that may contain HB(OH)+3. AlB2 is insoluble in dilute sulfuric acid, but soluble in nitric acid. AlB2 decomposes to form AlB12 above 920℃.
Storage condition
This product should be sealed and stored in a dry, cool environment, should not be exposed to the air for a long time, prevent moisture agglomeration, affecting the dispersion performance and use effect, should also avoid heavy pressure, do not contact with oxidants, according to the general cargo transport.
