SiB6 Powder: What You Need to Know Before You Buy?

Physical and chemical properties of silicon hexaboride

CAS: 12008-29-6  

EINECS: 234-535-8

Molecular formula: B6Si

Molecular weight: 92.952

Relative density: 3.0g/cm3

Melting point: 2200°C

Insoluble in water, resistant to oxidation, thermal shock, chemical attack, especially in thermal shock with high strength and stability. Higher grinding efficiency than boron carbide.

Main uses of silicon hexaboride

1. Used as various standard abrasives, grinding cemented carbide.  

2. Used as engineering ceramic materials, as various standard abrasives, grinding carbide. Also used as engineering ceramic materials, sandblasting nozzles, manufacture of gas engine blades and other shaped sintered parts and seals. Used as an anti-oxidant for refractory materials.

Hazardous properties of silicon hexaboride

This product is normally not hazardous to water, but do not discharge the material into the surrounding environment without government permission.

Storage conditions Silicon hexaboride will not decompose if used and stored in accordance with specifications. Keep sealed in a cool, dry place.

Basic properties of silicon hexaboride

Content: ≥99%

Particle size: 325 mesh, 1-3um

Property: black gray powder

Shape: granular  

Packing specification: aluminum foil bag

MOQ: ≥1kg

Silicon Hexaboride Terminology

Chemical formula SiB6. molecular weight 92.95. black crystal. relative density 2.47. hardness between diamond and ruby. Relative density 2.47. Hardness between diamond and ruby. Can conduct electricity. Insoluble in water. Oxidizes on the surface when heated in chlorine and water vapor. Oxidized directly in boiling nitric acid. Unchanged in molten potassium hydroxide. In hot concentrated sulfuric acid, it decomposes.

The SiB6 crystal structure contains interconnected icosahedra (20-sided polyhedra), icosahedral hexahedra (26-sided polyhedra), and isolated silicon and boron atoms. Due to 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 process

A low-cost high-purity silicon hexaboride production process, the boron trioxide and potassium borohydride, in argon protection, ball milling mix, pressed into a block, loaded into the vacuum carbon tube furnace, evacuation, 750 ℃ insulation for 5 hours; heating to 1250 ℃, continue to keep warm until the furnace pressure is slightly positive pressure, the reduction reaction is completely finished, will get the graphite crucible in the monomer boron and potassium hydroxide mixture, into distilled water heating cleaning The boron powder and silicon powder are mixed in the ball mill and loaded into the self-trailing combustion reaction kettle, the reaction kettle is evacuated, the vacuum is increased to 1 Pa, the tungsten wire is heated up, the zirconium powder is ignited, and the high temperature self-trailing combustion reaction is carried out. The purity of the produced silicon hexaboride is 99.5%, which is suitable for industrial production.