What is Boron Carbide?

Boron Carbide Powder belongs to the trigonal system. The unit cell contains 12 B and 3 C. The unit cell’s stereo diagonally connected C atoms are in an active configuration. They can be substituted by B atoms, forming a solid solution replacement.

B4C’s molecular weight is 52.25 and it has C21.74% and B78.25%. It is usually gray or black and has a Mohs Hardness of 9.35. The microhardness of 49GPa is second only to diamond.

B4C Powder has a melting temperature of 2450°C (decomposition). The coefficient for expansion at 1000degC (4.5×10-6degC-1) is 4.5×10-6degC-1. The thermal conductivity of B4C powder is 121.4W/m*k when it’s 100degC, and 62.79W/m*k when it’s 700degC. Hot-pressed products of B4C are used for wear-resistant and temperature-resistant parts. B4C powder is primarily used in the refractory industries as an anti-oxidant additive. Unshaped materials enhance the body’s strength and resistance to corrosion.

The properties and synthesis of Boron Carbide

B4C powder is synthesized in industry by reducing boron ahydride with excess Carbon:

2B2O3+7C-B4+6CO|

The synthesis reaction may be carried out either in an electric arc or a muffle oven. In a resistance-type furnace, the synthesis of B4C is better achieved by heating boron anhydride B2O3 with carbon C to a lower decomposition temperature than B4C. B4C is broken down into boron and carbon rich phase in the electric-arc furnace because of the high temperature. The reaction product may contain a lot of free C (20%-30%). As a result, the B4C obtained is of slightly inferior quality.

In order to synthesize B4C using an electric arc, boric acids (with a content greater than 92%), artificial graphite with a fixed carbon of greater than 95%, and petroleum coke with 85% fixed carbon are used. The theoretical dosage is calculated based on the reaction formula. The theoretical amount is approximately 2% higher. Each of artificial graphite and petroleum coke accounts for 50% of total carbon addition, which is then 3%-4% more than the theoretical amount. Add the three prepared raw materials to the arc and mix them in a ball-mill. B4C can then be obtained by reducing the furnace and carbonizing it between 1700-2300. Finaly, the frit will be sorted and cleaned, then crushed, ground and pickled.

(aka. Technology Co. Ltd., a global supplier of chemical materials and manufacturers with over 12 year’s experience, is a trusted source for high-quality nanomaterials and chemicals. The B4C powder that we produce is of high purity with a fine particle size. If you need lower, please call us.