固相反应法合成碳化硼纳米粉体

Synthesis of Boron Carbide Nano Powder by Solid State Reaction

以六方氮化硼和炭黑(或石墨)为原料,采用固相反应法合成了碳化硼粉体.碳源、反应气氛和温度对粉体合成产生重要影响.以炭黑为碳源,在1900℃真空下保温5 h,得到了平均粒径约为100 nm的碳化硼纳米粉体.与商业粉体相比,合成的粉体具有较好的烧结活性.在2000℃/30 MPa/1 h条件下烧结,样品的相对密度达到97.9%(商业粉体样品为93.1%),这可归结于合成的粉体具有细小的粒径、低的氧含量和一定程度的孪晶结构.

Boron carbide（B4C） powder was synthesized by solid state reaction of hexagonal boron nitride with carbon black（or graphite）.The phase assemblages of synthesized powders were influenced by carbon source,at-mosphere and temperature.Boron carbide powder with an average particle size of about 100 nm was obtained using carbon black as the carbon source at 1900℃ for 5 h in vacuum.The relative density of the sintered sample（2000℃/30 MPa/1 h） derived from the synthesized powder reached 97.9%,while that prepared from the commer-cial powder was 93.1%.The better sinterability of the synthesized powder than the commercial one can be attrib-uted to the finer particle size,lower oxygen content and the twin structure of the powder.