Polyether modified polydimethyl silane (PMPDMS) and α-SiC were mixed completely in a certain proportion and ground after drying at 120 ℃ for 12 h,then the mixture was put in a corundum crucible and heat treated in nitrogen.The phase compositions,specific surface area,density as well as the microstructure of the sintered lump were studied. The experiment was repeated by substituting α-SiC for B4C,and then the sintered lump was analyzed by XRD and SEM to make sure whether the PMPDMS coating in B4C particles formed p-SiC during heat treatment. The results show that: (1 ) PMPDMS coating in the surface of B4C particle forms p-SiC in the experiment;(2)the phase composition of α-SiC changes after surface modification, the specific surface area increases, the density of sintered lump enhances, and the microstructure becomes denser,indicating a reinforced sintering activity.%将聚醚改性聚二甲基硅烷(PMPDMS)与α-SiC微粉按一定比例充分混合,于120℃烘干12 h后碾碎,放入刚玉坩埚内,在N2保护下以一定的加热制度进行热处理,然后分析其相组成、比表面积、烧结块密度及其显微结构的变化；同时以B4C微粉取代α-SiC微粉做同样处理后进行XRD和SEM分析,以确定包覆在B4C微粉表面的PMPDMS在热处理过程中是否生成了β-SiC.结果表明:1)包覆在B4C微粉表面的PMPDMS在试验确定的热处理条件下可以生成β-SiC；2)表面改性后α-SiC微粉相组成发生一定改变,比表面积增大,用其制成的烧结块的密度增大,显微结构更加致密,表明其烧结活性增强.
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