The crystal lattice of boron-carbide crystals is D3d5R3m. The rhombohedral lattice can be described as an icosahedron-shaped primitive cubic cell that extends diagonally in the space. The c-axis is the same as the diagonal of the area. A linear chain is formed by connecting three boron-atoms to an adjacent icosahedron. Three of the 12 icosahedral position are found on the chain. If B is due to a position caused by an icosahedron while C is in a chain, the stoichiometry is B4C.
1. Basic properties and applications for boron carbide
1) Low density
B4C density is small at 2.52g/cm3. The empirical formula (9) can be used to express the relationship between carbon content and density in the homogeneous area.
r=2.4224+0.00489C%(9)
Because of the low density of the boron carbide, when the density is increased, its performance will reach the standard boron carbide, with high strength, high toughness, and many other excellent performances. Therefore, it can be used for lightweight armor in order to reduce the body weight of vehicles and tanks. Save energy.
2) Hardness of the material and wear resistance
B4C exhibits super hardness, and has a high wear resistance. B4C’s Vickers Hardness in homogeneous areas increases as the C content increases. The hardness is 29.1 GPa when the carbon is 10.6%; at 20% carbon, it can reach 37.7 GPa. At high temperature, its hardness remains high (>30GPa). You can express the change in hardness with temperature by using empirical formula (10).
H=H0-exp(-aT)(10)
The formula is: H0-the hardness of the material at room temperature
Temperature is T.
Carbon is a constant.
This formula applies to 201700. B4C is second only to cubic BN and diamond in terms of hardness.
B4C wear resistance increases with temperature. As the temperature increases, the friction coefficient of B4C decreases. It drops to 0.05 between 20 and 1400, while the friction rate continues to decline. B4C’s super hardness and friction properties have made it a popular nozzle for sandblasting.
(aka. Technology Co. Ltd., a global supplier & producer of high-quality chemical materials and Nanomaterials with more than 12 years experience in the field. The B4C Powder produced by our company is of high purity and has a low impurity level. If you require lower, please contact our company.