SiB6 Silicon Boride Powder

SiB6 Silicon Boride Powder

Product Name: silicon hexaborate

English Name: boron silicide (b6si);  Boron silicide;  Silicon boride;  Hexaboron silicide

CAS:12008-29-6 [1] 

EINECS:234-535-8

Molecular formula: b6si

Molecular weight: 92.952

Relative density: 3.0g/cm3

Melting point: 2200 ℃

Application of silicon hexaborate:

1. B6si can effectively promote the sintering of boron carbide ceramics and improve the

 mechanical properties of materials.

2. Because silicon hexaborate has heat resistance and high impact resistance, it is relatively

cheap, so it is often used in resin grinding wheels and as the main abrasive.

Explanation of silicon hexaborate terms: chemical formula sib6. Molecular weight 92.95. 

Black crystal. The relative density is 2.47. The hardness is between diamond and ruby. It

 can conduct electricity. Insoluble in water. When heated in chlorine and steam, the surface

 can be oxidized. It can be oxidized directly in boiling nitric acid. Unchanged in molten

 potassium hydroxide. It decomposes in hot concentrated sulfuric acid. Explanation of 

preparation terms: the mixture of silicon and boron can be directly heated, the excess silicon

 can be removed with hydrofluoric acid and nitric acid, and then the silicon triboride (b3si) in

 the mixture can be decomposed with molten potassium hydroxide. The crystal structure of

 sib6 consists of interconnected icosahedron (20 faceted polyhedron), icosahedron (26 faceted

 polyhedron) and isolated silicon and boron atoms. Due to the size mismatch between silicon

 and boron atoms, silicon can be used to replace boron in B12 icosahedron until the limit

 stoichiometric ratio corresponding to sib2.89 is reached.

High purity silicon hexaborate process:

A low-cost and high-purity silicon hexaborate production process, boron trioxide and potassium

 borohydride, in argon protection, after ball milling and mixing, are pressed into blocks, loaded

 into a vacuum carbon tube furnace, evacuated, and maintained at 750 ℃ for 5 hours; Raise

 the temperature to 1250 ℃ and continue to maintain the temperature until the pressure in the

 furnace is slightly positive, and the reduction reaction is completely completed. Put the mixture

 of monomer boron and potassium hydroxide in the graphite crucible into distilled water for heating,

 cleaning and drying to obtain boron powder; The boron powder and silicon powder are milled and

 mixed, and then loaded into the self creeping reaction kettle. The reaction kettle is evacuated, and

 the vacuum degree is 1 Pa. The tungsten wire is heated by electricity, and the zirconium powder is

 ignited. The high-temperature self creeping reaction is carried out. The reaction is completed, the

 temperature is reduced, and the impurities are removed to obtain high-purity silicon hexaborate With

 boron trioxide and potassium borohydride as raw materials, the raw material cost is relatively low, 

and the whole process is reasonable and controllable. The purity of silicon hexaborate produced is 

99.5%, which is suitable for industrial production.