Characteristic

Silicon borides (also known as boron silicides) are lightweight ceramic compounds formed between silicon and boron. Several stoichiometric silicon boride compounds, SiBn, have been reported: silicon triboride, SiB3, silicon tetraboride, SiB4, silicon hexaboride, SiB6, as well as SiBn (n = 14, 15, 40, etc.).Both SiB4 - x and SiB6 become superficially oxidized when heated in air or oxygen and each is attacked by boiling sulfuric acid and by fluorine, chlorine, and bromine at high temperatures. The silicon borides are electrically conducting. 

Chemical formula：B₄Si

Molar mass:71.33 g/mol

Appearance:solid

Density:2.4 g/mL at 25 °C

Melting point:1870 °C

Application

The tetraboride was used in the black coating of some of the space shuttle heat shield tiles.

SiB4_MSDS.pdf