Polimerik öncü yöntemiyle bor karbür üretimi

Boron carbide is used many applications due to its outstanding properties. It is used as abrasive powder for lapping, polishing and water jet cutting of metallic alloys and ceramic materials and as raw material for producing metal borides. When it is sintered, it is used as micro blast and spray nozzle, ceramic bearing, ballistic armor, welding and thermal spraying electrodes, control rod, shielding material and neutron detector for nuclear applications. In recent years, researchers have focused on polymeric precursor method to produce boron carbide. This method gives big opportunity to replace commercial method owing to cheap and non-toxic raw materials and low carbothermic reduction temperature (1200-1500 °C). Reactants can be obtained with superior reactivity and it provides synthesizing boron carbide at low temperature. However, producing ester without impurity is a challenge. In this study, in order to synthesize boron carbide as powder form at low temperature, high purity mannitol borate which was produced by BOREN Organic/Polymer Laboratory was used. Characterization of mannitol borate was performed by FT-IR and TG-DTA analyses. Various ratios of C/B2O3 of decomposed powders were studied. Obtained boron carbide powders were characterized by XRD, SEM and laser light scattering. Synthesis of boron carbide powder with certain amount of free carbon was achieved at 1400°C 5 h and 1300°C for 6 h from decomposed powders whose ratios of C/B2O3 are closer to stoichiometric ratio. Closing to stoichiometric ratio means that that reaction was achieved at high efficiency. D50 values of boron carbide powders were determined as 7.957 and 5.472 µm and particle shapes were found equiaxed. Keywords: Boron carbide, low temperature synthesis, polymeric precursor method, boric acid, mannitol.