Boron carbide is an important strategic material due to high hardness, mechanical properties and neutron absorption cross-section which make it an attractive material for micro-electronic, nuclear, military and medicine. In this study, we aimed to develop a cost effective and low-temperature manufacturing process to synthesize boron carbide from cheap raw materials. Nanocrystalline boron carbide was successfully synthesized via a hydrothermal method followed by the carbothermal reduction reaction (CRR). Boron carbide (B_4C) powder has been prepared by using an aqueous solution of boric acid and lactose, which transferred to outcalve and heated at 280°C for 24 h. Then the produced materials were calcined, followed by CRR under an argon atmosphere. The influence of boron to carbon molar ratio of the initial mixtures on the properties of both calcined samples and final products were thoroughly investigated. The calcined samples were charectrized via FT-IR and thermal analysis. In contrary, samples produced after CRR were examined with the help of XRD, Raman, FT-IR and FE-SEM. The examination of calcined samples confirm the the formation of borate ester compounds during calcination process. The results of XRD and FT-IR studies after carbothermal reduction reaction at 1500°C for 3h indicate that the product consists of pure nano-crystalline B_4C. Raman spectra revealed that B_4C was formed according to Raman peaks at 270, 320, 481, 531, 728, 830, 1,000 and 1,088cm~(-1). FE-SEM images show that a hexagonal nanocrystalline boron carbide is formed with different shapes ranging from swords, needles to spherical like structures depending on the boron to carbon ration of the starting mixture.
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