Synthesis And Characterization Of B-C-N Ternary Compounds

One of the key areas that have attracted a lot of attention in current light element materials research field is the experimental synthesis of novel material BCN. On the basis of summarizing the theoretical and experimental development of BCN ternary compound, we study the experimental synthesizing of B-C-N ternary compounds by the catalytic pyrolysis of organic precursors and mechanical alloying method. Using Fe and MgO as catalyst, Dimethylamino borane(DMAB) as raw material, we synthesize B-C-N compounds through catalytic dehydrogenation. Using graphite and h-BN as raw material, selecting different ball-to-powder ratio, we synthesize B-C-N compounds through mechanical alloying method. The morphology, phase forms, chemical compositions and bond structures of synthesized products are characterized by scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and fourier transform infrared spectroscopy (FTIR). Thermo-properties of B-C-N compounds synthesized by mechanical alloying method are studied.At pyrolysis temperature in the range of 500~1000℃for 0.5~2h, the turbostratic structure B-C-N compounds are synthesized by the catalytic pyrolysis of organic precursors on the action of Fe catalysis in the vacuum condition. The micro-morphology products is regular nemaline, and the diameter is about 0.5~1μm. The atomic ratio of B, C, N is about 1:1:1. Further Fourier transformed infrared measurement indicates that B-C-N, C-N, B-C and B-N bonds exist in all the products prepared in different pyrolyze conditions.At pyrolysis temperature in the range of 500~1000℃for 0.5~2h, the turbostratic structure B-C-N compounds are synthesized by the catalytic pyrolysis of organic precursors on the action of MgO catalysis in the vacuum condition. The microcosmic appearance of products is massive texture in different size, about 1~3μm. The atomic ratio of B, C, N is about 0.28:0.33:0.38. Further Fourier transformed infrared measurement indicates that B-C-N, C-N, B-C and B-N bonds exist in all the products prepared in different pyrolyze conditions.The B-C-N compounds with random layer graphite structure are synthesized by mechanical alloying method of graphite powder and h-BN powder with different ball-to-powder ratio. The products are a series of B-C-N compounds from amorphous to turbostratic structure. When the milling time lasted 240h, products appear amounts of hexagonal B-C-N crystalling phase. Further Fourier transformed infrared measurement indicates that B-C, C-N, B-N and B-C-N bonds exist in the products. In additional, the products contains C=N bond when the ratio of ball-to-powder is 20:1. The B-C-N compounds by mechanical alloying method possess good thermostability and strong inoxidizability whether in the nitrogen or atmospheric environment.