Aluminium dodecaboride
| Names | |
|---|---|
| IUPAC name
Aluminium dodecaboride
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| Other names
AlB12
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| Identifiers | |
3D model (JSmol)
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| ECHA InfoCard | 100.031.737 |
| EC Number |
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PubChem CID
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| Properties | |
| AlB12 | |
| Molar mass | 156.714 g/mol[1] |
| Appearance | Yellow to black solid[1] |
| Density | 2.55 g/cm3[1] |
| Melting point | 2,070 °C (3,760 °F; 2,340 K)[1] |
| insoluble | |
| Solubility | soluble in hot nitric acid (decomposes),[2] soluble in nitric acid (decomposes),[3] soluble in sulfuric acid (decomposes)[3] |
| Structure | |
| Tetragonal (α-form) Orthorhombic (β-form) | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Aluminium dodecaboride (AlB12) is a superhard chemical compound with 17% aluminium content by weight.
It is the hardest boride of the aluminium-boron system, which also includes AlB10, AlB4, AlB2 and AlB.
Properties
[edit]There are two crystalline forms, α-AlB12, and γ-AlB12. Both forms are very similar and consist of a framework with three-dimensional networks of B12 and B20 units.[4] The phase β-AlB12 is now believed to be the ternary boride C2Al3B48.[5]
Preparation
[edit]The β-form can be prepared by the reaction of boron(III) oxide with sulfur and aluminium, then adding carbon to the mixture.
Uses
[edit]The extreme hardness of AlB12 makes it a favorable component of PCBN inserts, which are mainly used in cutting and grinding to replace diamond or corundum.
See also
[edit]Footnotes
[edit]- ^ a b c d Haynes, William M., ed. (2011). CRC Handbook of Chemistry and Physics (92nd ed.). Boca Raton, FL: CRC Press. p. 4.45. ISBN 1-4398-5511-0.
- ^ Martienssen, Werner; Warlimont, Hans (2005). Martienssen, Werner; Warlimont, Hans (eds.). Springer Handbook of Condensed Matter and Materials Data. Springer-Verlag. p. 1025. Bibcode:2005shcm.book.....M. ISBN 9783540443766.
- ^ a b Rebekoff Reeve, Martin (1991) Method of producing an aluminium boride. EP 0130016 B1
- ^ Higashi, Iwami (2000). "Crystal chemistry of α-AlB12 and γ-AlB12". Journal of Solid State Chemistry. 154 (1): 168–176. Bibcode:2000JSSCh.154..168H. doi:10.1006/jssc.2000.8831.
- ^ Matkovich, V. I; Giese, R. F; Economy, J (1965). "Phases and twinning in C2Al3B48 (β-AlB12)". Zeitschrift für Kristallographie. 122 (1–2): 108. Bibcode:1965ZK....122..108M. doi:10.1524/zkri.1965.122.1-2.108.