AN EXPERIMENTAL INVESTIGATION OF B4C PREPARATION FROM BORIC ACID – POLYMERIC GEL PRECURSORS AT LOW TEMPERATURE

Abstract

In this study, boron carbide (B4C) has been effort prepared by using boric acid (H3BO3) as a boron source, and three types of polymer materials as carbon source (glucose, polyvinyl alcohol (PVA) and corn starch) by developing the carbothermal process using reduced gas (H2) flow. Aqueous solutions of boric acid in presence one of the polymers forms astable gel. Pyrolysis temperature 350°C was used after getting the gel. Then, the pyrolysed product is calcined at a range of (600 – 900)°C for 2 hours. XRD analyses showed that B4C could be produced by using boric acid and PVA as raw materials after calcination at 800°C. Also, the addition of magnesium sulfate into the mixture reactants promoted the reaction and resulted in an increase in the boron carbide content. The SEM images and particle size distribution tests showed that the prepared B4C powder has a median size of 460 nm.