Paper presented at the 7th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Turkey, 19-21 July, 2010.
Boron carbide, B4C, is the third hardest known material next to diamond and boron nitride. Reasonable cost of production, low density, and high chemical inertness makes boron carbide an attractive material for micro-electronic, military, space and medical applications. Boron has a high neutron absorption cross section and hence any compound containing boron, especially if it has a good mechanical strength, is of great interest in nuclear industry. Other properties of B4C make this compound to be highly used in nuclear reactor. Using reduction reaction of boron oxide by carbothermal process, B4C, free of impurities, was produced. Boron loss during the process, in the form of B202 gas; a common problem in B4C production, was minimized by adjusting the stoicheometry of feeding materials. Likewise, carbon residue was eliminated by taking appropriate composition at the starting point. The result of number of experiments showed that production of boron carbide is highly dependent on the phase change of reactant boron oxide from solid to liquid and from liquid to gaseous boron hypo-oxides and then the interaction with carbon and carbon monoxide.