,Silicon Boride Powder
Silicon Boride (also known as boron silicide) is a lightweight ceramic compound made up of silicon and boron. There are silicon triboride, silicon tetraboride, silicon hexaboride, and so on.
Silicon hexaboride or hexaboron silicide is a glossy black gray powder. The chemical formula is SiB6. The molecular weight is 92.95. The relative density is 2.47 g/cm3, the melting point is 2200℃. The hardness is between diamond and ruby. Silicon hexaboride can conduct electricity. It is insoluble in water. When heated in chlorine and water vapor, the surface can be oxidized.
Physicochemical Properties of Silicon Boride Powder
The SiB6 crystal structure consists of interconnected icosahedrons (polyhedrons with 20 faces), icosahedrons (polyhedrons with 26 faces), and isolated silicon and boron atoms.
It is insoluble in water and resistant to oxidation, thermal shock, and chemical erosion. Especially under thermal shock, it has high strength and stability. The grinding efficiency is higher than boron carbide.
Surface oxidation occurs when SiB6 is heated in air or oxygen and is eroded at high temperatures by boiling sulfuric acid and fluorine, chlorine, and bromine. Borides are electrically conductive. Hexamborides have a low thermal expansion coefficient and high thermal neutron cross-section.
|Silicon Boride Powder Properties|
|Other Names||silicon hexaboride, SiB6 powder|
|Appearance||dark grey to black powder|
|Solubility in H2O||insoluble|
Preparation Methods of Silicon Boride Powder
The mixture of boron and silicon can be heated directly, the excess silicon can be removed with HF and HNO3, and the B3Si in the mixture can be decomposed with molten KOH.
Applications of Silicon Boride Powder
1 Used as various standard abrasives and grinding cemented carbide;
2 used as engineering ceramic material, sandblasting nozzle, manufacturing gas engine blade, and other special-shaped sintering parts and seals.
3. Used as an oxidant for refractories.