|DENS - Density (Specific Gravity)||2.5|
|GSPT - Frit Softening Point||2720K, Boils at 3770K|
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.
Out Bound Links
In ceramics, when we speak of deflocculation, we are almost always talking about making a casting slip. Glazes can also be deflocculated (to reduce water content and densify laydown). Deflocculation is the process of making a clay slurry that would otherwise be very thick and gooey into a thin po...
In Bound Links
Hot pressing is a process used to fabricate ceramic parts (often from non-oxide powders like BIN, SiC or B4C). The process involves the simultaneous application of pressure and heat to a 'green' component or powder under a controlled atmosphere (depending on the material being processed). Since pres...