Production of boron carbide powder by carbothermic reduction from boron oxide and petroleum coke or carbon active

Abstract

Carbothermic reduction process is recognised as a beneficial method to produce boron carbide powder. In the present article, this method was utilised to produce a boron carbide powder using commercial purity raw materials. Boron oxide being a source of boron and carbon active and petroleum coke as reducing agents were used. Mixtures of boron oxide and carbon holding material with a particle size of <44 μm were put in a graphite crucible and heated under a flow of argon atmosphere in a tube furnace to 1400–1550°C for 1–5 h, resulting in the formation of boron carbide powder with or without unreacted starting raw materials. It was found that the optimum weight ratio of boron oxide to carbon bearing material was 1·8 and 1·6 for petroleum coke and carbon active respectively. Heat treatment of these mixtures at 1470°C for 5 h resulted in the synthesis of boron carbide powders, which contained 0·75 and 0·65 wt-% free carbon respectively.