Sol-Gel synthesis and characterization of SiC–B4C nano powder

Abstract

In the present research, SiC–B4C nano powders were synthesized through sol–gel process in water–solvent–catalyst–dispersant system. In order to evaluate the formation mechanism of the product during sol-gel process, TEM, SEM, DTA/TG, BET, XRD, FTIR and DLS analysis methods were employed. The nanometric size of precursor was controlled by dispersing agents and controlling pH inside the sol. DLS analysis revealed that the particles of the precursor inside the sol were below 10 nm. FTIR results indicated that the (Si–O–B) bonds were formed in the dried gel powder, due to hydrolysis and condensation reactions. DTA analysis confirmed that the synthesis temperature was lower than 1400 °C. XRD results implied the presence of cubic β-SiC and the rhombohedral B4C phases, which were formed simultaneously in the SiC–B4C nanopowder. BET analysis indicated a high surface area for the particles of about 171.42 m2/g, and that the surfaces of these particles were meso porous. SEM analysis exhibited that SiC– B4C particle size was in the range of 20–40 nm with homogenous morphology. Ultimately, the TEM/EDS microstructural analysis showed that B4C and SiC particles were formed simultaneously and uniformly in the final product.