Synthesis of highly dispersed boron carbide from nanofibrous carbon

Abstract

The results of a study of the synthesis of fine-grained boron carbide powder and some of its characteristics are presented in the article. Boron carbide was obtained by synthesis from elements (boron and nanofibrous carbon (NFC)) in an inert gaseous atmosphere. The presence of boron carbide in the samples was established by X-ray phase analysis. The impurity content was determined by X-ray fluorescence spectroscopy. The shape and size of the boron carbide particles were determined by transmission and scanning electron microscopy with the use of local energy-dispersive X-ray microanalysis; this made it possible to determine that boron and carbon were mostly present in them. The specific surface area and porosity of the samples were determined using the BET method. The thermo-oxidative stability of boron carbide was studied by simultaneously using thermogravimetry and differential scanning calorimetry. The synthesized boron carbide at a temperature of 1900°C and holding time of 15–40 min had an impurity content no higher than 1.5 wt % and particle sizes of 100–500 nm.