Silicon hexaborides are the newest materials for electronics

Physical and chemical properties of high purity silicon hexaboride

Density: 3.0g /cm3

Melting point :2200°C

Molecular Formula :B6Si

Molecular weight :92.951

Exact Mass :92.952

Refractive index :1.337

Storage condition: Sealed in a cool dry place.

Water solubility: 200 g/L (25 ºC)

Stability: does not decompose when used and stored according to specifications. The hardness is between diamond and ruby. Can conduct electricity. Insoluble in water. When heated in chlorine and water vapor, the surface can be oxidized. It can be oxidized directly in boiling nitric acid. Does not change in molten potassium hydroxide. In hot concentrated sulfuric acid, it is decomposed.

Silicon hexboride =92.95, density 3.0g/cm3, melting point 2200℃, shiny black gray powder, insoluble in water, oxidation resistance, thermal shock resistance, chemical erosion resistance, especially under thermal shock has high strength and stability. With excellent thermoelectric property, as a P-type high-temperature thermoelectric material to replace boron carbide, its hot end use temperature can reach 1200℃. It can be used as engineering ceramic material, sandblasting nozzle, blade and other special-shaped sintered parts and seals of gas engine.

Sio2 powder hexaboride product characteristics

CAS: 12008-29-6

EINECS: 234-535-8

Purity: ≥99%

Particle size: 325 mesh, 1-3μm

Appearence: black gray powder

Shape: granular/powder

The product is insoluble in water, oxidation resistance, thermal shock resistance, chemical erosion resistance and other characteristics, especially under thermal shock has a high strength and stability; Grinding on boron carbide, more than silicon carbide.

High purity silicon hexaboride noun explanation

SiB6. Molecular weight 9295. Black crystal. Relative density 247. The hardness is between diamond and ruby. Can conduct electricity. Insoluble in water. When heated in chlorine and water vapor, the surface can be oxidized. It can be oxidized directly in boiling nitric acid. Is invariant in molten potassium nitrogen oxide. In hot concentrated sulfuric acid, it is decomposed.

Explanation of preparation terms: The mixture of silicon and boron can be heated directly, with hydrofluoric acid and nitric acid to remove excess silicon, and then with molten potassium hydroxide to the mixture = silicon boride (B3Si) decomposition. The SiB6 crystal structure contains interconnected icosahedra (20-sided polyhedra), icosahedra hexahedra (26-sided polyhedra) and isolated silicon and boron atoms. Because of the size mismatch between silicon and boron atoms, silicon can be substituted for boron in the B12 icosahedron until the limiting stoichiometric ratio corresponding to SiB2.89 is reached.

High purity silicon hexaboride preparation

A low-cost six boride high purity silicon production process, the boron trioxide and potassium borohydride, the argon gas protection, ball mill mixing after pressed into pieces, then packed in vacuum tubes furnace, fit, 750 ℃ heat preservation 5 hours to heat up to 1250 ℃, continue to heat preservation, micro positive pressure until the furnace pressure, reduction reaction is completed, will be in the graphite crucible of monomer boron and potassium hydroxide mix, Into distilled water heating cleaning, drying, get boron powder: the boron powder and silicon powder ball mill mixing after loading the tendril combustion reaction kettle, the reaction kettle time, vacuum degree to 1 mpa, sending up tungsten, zirconium powder, high temperature since the tendril combination reaction, reaction, cooling in removing impurity, six boride get high purity silicon with boron and boron trioxide radon potassium as raw material, raw material costs are relatively low, The whole process is reasonable and controllable, the purity of the silicon hexaboride produced is 99.5%, which is suitable for industrial production.

Applications of sio2 powder hexaboride

1. As a P-type high-temperature thermoelectric material to replace boron carbide, can be used as a variety of standard abrasive, grinding hard alloy.

2. It is also used as engineering ceramic material, sandblasting nozzle, and the blade of gas engine and other special-shaped sintered parts and seals.

3. Used as an anti-oxidant for refractories.