Boron Carbide(B4C)-Superhard Materials

详情

Key Properties Boron carbide is characterised by its: ��������� Extreme hardness ��������� Difficult to sinter to high relative densities without the use of sintering aids ��������� Good chemical resistance ��������� Good nuclear properties ��������� Low density Property Density (xxxxx*3) 2.*2 Melting Point (�C) ***5 Hardness (Knoop **0g) (xxxxx*2) ********0 Fracture Toughness (xxxxx-�) 2.9 - 3.7 Young's Modulus (GPa) **0 - **0 Electrical Conductivity (at *5�C) (S) **0 Thermal Conductivity (at *5�C) (W/m.K) *0 - *2 Thermal Expansion Co-eff. x***6 (�C) 5 Thermal neutron capture cross section (barn) **0 Applications Abrasives Due to its high hardness, boron carbide powder is used as an abrasive in polishing and lapping applications, and also as a loose abrasive in cutting applications such as water jet cutting. It can also be used for dressing diamond tools. Nozzles The extreme hardness of boron carbide gives it excellent wear and abrasion resistance and as a consequence it finds application as nozzles for slurry pumping, grit blasting and in water jet cutters. Nuclear applications Its ability to absorb neutrons without forming long lived radio-nuclides make the material attractive as an absorbent for neutron radiation arising in nuclear power plants. Nuclear applications of boron carbide include shielding, and control rod and shut down pellets. Ballistic Armour Boron carbide, in conjunction with other materials also finds use as ballistic armour (including body or personal armour) where the combination of high hardness, high elastic modulus, and low density give the material an exceptionally high specific stopping power to defeat high velocity projectiles. Other Applications Other applications include ceramic tooling dies, precision toll parts, evaporating boats for materials testing and mortars and pestles.