【摘要】 利用水热法合成了立方氮化硼(cBN),利用立方氮化硼在特定反应条件下的自发团聚现象,提出了一种使混合物中的立方氮化硼在反应过程中自发纯化的新方法.提高原料浓度、反应温度和搅拌速度有利于获得较大粒径的立方氮化硼和尺寸分布均匀的团聚颗粒,但提高反应压力则会导致相反的结果.探讨了自团聚现象在生长大尺寸立方氮化硼晶体以及非均相合成中的潜在应用价值.更多还原

【Abstract】 Hydrothermal method was used to synthesize cBN.However,it was found that BN samples prepared by this method were usually mixtures of cBN,hBN and other phases of BN,which is a disadvantage for the further application.So,it is expected to explore new methods by which cBN can be easily separated from the mixture.The pre-sent paper deals with a method based on the self-aggregation phenomenon of cBN crystallites to prepare pure millimmeter-size cBN agglomerates under specific hydrothermal conditions.The particle size and its uniformity of the agglomerates can be improved by increasing the reaction temperature,concentration of reactants,and the homogeneity of reaction solution.In contrast,increasing the pressure results in an opposite trend.A simple model was proposed to explain the mechanism of the self-aggregation phenomenon.更多还原