What is the Definition of Boron Carbide (B4C)?

Boron Carbide (B₄C) is a grey-black colored super hard abrasive with metallic luster. It is one of the hardest man-made materials available in commercial quantities that have a finite melting point low enough to permit its relatively easy fabrication into shapes. Its hardness is only second to diamond and cubic boron nitride, with Mohs hardness 9.36 and microscopic hardness 5400-6300kg/mm¬2, giving outstanding resistance to abrasive wear.
 
Boron Carbide is produced by reacting and fusing boric acid (H₃BO₃) and graphite powder (or toner/carbon material) in an electric arc furnace at high temperature of 1700~2500℃. The composition ranges from B4C at 78.25 wt% boron to at least B_6.5C at 85.4 wt% boron. It tends to contain second-phase graphite and it is this property that has a major influence on the strength of the material. It has a 4-point flexural strength of 50,000-70,000 psi and a compressive strength of 414,000 psi, depending on density. Boron Carbide also has a low thermal conductivity (29-67 W/mK) and has electrical resistivity ranging from 0.1-10 ohm-cm.
 
Boron Carbide is chemically inert and has good resistance to acids, but less resistant to oxidation than silicon carbide. It begins to be oxidized when heated to 500℃ in the air; when temperature comes up to 800~900℃, its oxidation is more significant. It also has a unique property of a high neutron absorbing cross section and refractory.

Boron Carbide was once used for replacing diamond grinding hard alloy cutter. Its sintered products are available to replace diamond as grinding wheel dresser, which has a wide application in precision grinding of carbon tungsten alloy, carbon titanium alloy, sintering corundum, artificial stone, special ceramic, and other hard materials and products.

Besides abrasives, it also has other popular industrial applications including: Anti-oxidant in carbon-bonded refractory mixes; Armor; Aerospace; Nuclear applications such as reactor control rods and neutron absorbing shielding，Wear parts such as blasting nozzles, wire-drawing dies, powdered metal and ceramic forming dies, thread guides, etc.

For your purchasing, you may consider the abrasive glossary or need some charts (grit size, standards, and so on). To buy Boron Carbide, please click the product name to get the list. Or, you can let us help you to "Guide" first by Boron Carbide Specifications.