Boron Carbide

Description: B4C

Notes

Commonly designated B4C (78.3% carbon theoretical but free carbon can be present in some grades). Sintered B4C is the hardest material available after diamond (it is harder than silicon carbide and carborundum) and BIN (however unlike BIN it is available in tonnage amounts). Boron carbide is a non oxide ceramic made by reacting various borates with carbon (coatings are formed by reacting borate vapors and carbon gases).

B4C parts have a low specific gravity; high wear, heat and chemical resistance; high strength; and neutron absorbing properties (in nuclear reactors). However it's brittle nature and tendency to oxidize or react with various metals when heated limits its use in some abrasion and molten metal processing applications (however it can be employed to make refractory metal borides and light weight ceramic metal composites e.g. aircraft armor).

Very high densification can be achieved by hot pressing extremely fine powders under vacuum or controlled atmosphere. B4C parts can also be cast from very fine powders using the traditional deflocculation and plaster casting methods. Parts need to be fired to 1500C+.

B4C reacts with halogens and is used as a precursor in the production of nonoxide boron chemicals (e.g. BCl3) using the CVD (chemical vapor deposition) process.

Related Information

Links

Oxide	Analysis	Formula

Materials	Alumina
Materials	Boron Nitride
Materials	Silicon Carbide
Materials	Barium Titanate
Typecodes	Abrasive Resistant Super Hard Material These materials are generally available in granular form, the particles are cemented together using frits to produce abrasive products. However, powdered and slurried forms of these materials can also be formed and fired by various means to produce hard materials.
Typecodes	Non-Oxide Material Many of these materials are not used in traditional ceramics but they have such incredible properties that some have been included in this database.
Glossary	Deflocculation Deflocculation is the magic behind the ceramic casting process, it enables slurries having impossibly low water contents and ware having amazingly low drying shrinkage
Glossary	Hot Pressing

Data

Frit Softening Point	2720K, Boils at 3770K
Density (Specific Gravity)	2.5

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