【摘要】 以硼酸、硅溶胶、片状石墨为原料,采用碳热还原法制备SiC-B₄C复合粉末。研究了反应温度对SiC-B₄C复合粉末的烧失率和物相组成的影响。采用X射线衍射仪（XRD）、激光粒度分析仪（LPSA）对实验样品的物相组成、粒度大小及其分布进行分析。结果表明:在反应温度达到1500℃以上时,采用碳热还原法可以成功合成出SiC-B₄C复合粉末。合成SiC-B₄C复合粉末的最适温度与硼酸用量有关。当硼酸用量为理论配比时,合成SiC-B₄C复合粉末的适宜反应温度为1500℃;当硼酸过量30%时,合成Si C-B₄C复合粉末的适宜反应温度为1550℃。当硼酸过量30%时,在1550°C下合成的SiC-B₄C复合粉末中位粒径为0.14μm。更多还原

【Abstract】 SiC-B₄C composite powder was prepared by carbothermal reduction method using boric acid,silica sol and flake graphite as raw materials. The effects of reaction temperatures on the loss on ignition rate and the phase composition of SiC-B₄C composite powder were studied. X-ray diffractometer（XRD） and laser particle size analyzer（LPSA） were used to analyze the phase composition,particle size and distribution of the experimental samples. The results show that SiC-B₄C composite powder can be successfully synthesized by the carbothermal reduction method when the reaction temperature reaches above 1500℃. The optimum reaction temperature for the synthesis of SiC-B₄C composite powder is related to the amount of boric acid. The suitable reaction temperature for the synthesis of SiC-B₄C composite powder is at 1500℃ when the amount of boric acid is the theoretical ratio, and it is at 1550℃ when the excess of boric acid is 30%. The median particle size of the SiC-B₄C composite powder synthesized at 1550℃ is 0.14μm when boric acid exceeds 30%.更多还原