Microwave-assisted sol–gel synthesis of neutron-absorbed nano-sized 10B-enriched B4C powders

Abstract

In the present work, nano-sized 10B-enriched boron carbide (B4C) powders were prepared by carbothermal process using 10B-enriched boric acid (H3BO3) and citric acid (C6H8O7·H2O) as raw materials, and the precursor was prepared by sol–gel method. In order to reduce the residual carbon in the final products, an effective decarbonization method was explored with a controlled final calcination technology. In the resultant B4C powders, the abundance of the 10B element was tested to be 57.50 % by ICP-MS. The microstructure and phase composition of the powders were characterized by SEM, TEM and XRD. X-ray pure B4C was obtained, and the particle size was estimated to be around 100 nm with a uniform distribution. The specific surface area of the powders tested by BET method was 38 m2/g. The precursor of B4C powders was synthesized via microwave combustion method with 10B-enriched boric acid (H3BO3) and citric acid (C6H8O7·H2O). The products showed a uniform morphology with a finer grain size. An effective decarbonization method was explored with a controlled final calcination technology.