详细设计基于ssh架构的物流管理系统中分站管理模块与配送中心管理模块的设计_毕业论文.doc

ZrO2/SiC-MoSi2纳米复合陶瓷制备中纳米颗粒 的均匀分散研究 学生姓名： 班级： 指导老师：××× 摘要：在纳米复合陶瓷中，纳米颗粒必须均匀分散在亚微米基体中，才有可能在烧结过程中均匀长大，避免因过分长大而失去其特有的增韧作用。而纳米颗粒的团聚是造成纳米颗粒过分长大的主要原因。因此，怎样更好的使纳米颗粒均匀分散是制备优良纳米复合陶瓷的关键。 本文采用多相悬浮混合法，对ZrO2/SiC-MoSi2复合材料制备过程中纳米SiC和ZrO2颗粒均匀分布在基质MoSi2中的分散工艺进行了研究。以水和无水乙醇为分散介质,以PEG、PAA－NH4和PMAA-NH4作为分散剂分别对纳米SiC和ZrO2进行分散实验。同时研究了SiC纳米颗粒的表面预处理工艺对其分散性的影响。Zeta电位测试和沉降实验结果表明，采用550℃、2h的煅烧工艺处理纳米SiC可有效改善其分散性。使用水作为分散介质的分散效果均比乙醇好。ZrO2在分散剂为PAA-NH4，SiC在分散剂为PMAA-NH4时的分散效果最好。各种分散剂的加入量为0.2 wt%时的分散效果最好。ＳＥＭ结果表明通过以上最佳分散工艺得到的ZrO2/SiC-MoSi2复合粉体的均匀性较好。 关键词：分散 纳米SiC颗粒 纳米ZrO2颗粒 MoSi2 指导老师签名： Studies on the uniformly dispersing of nanoparticles in ZrO2/SiC-MoSi2 Ceramic Nanocomposite Student name : Class: Supervisor: ××× Abstract:When preparing ceramic nanocomposites,the most importance is that nanoparticles are uniformly in sub-micron matrix. Otherwise the nanoparticles will grows excessively in the course of sintering, which induce the toughening function lost. The main reason of nanoparticles growing excessively is reuniting of nanoparticles. Therefore, the key to prepare excellent ceramic nanocomposites is that nanopartiles are dispersed uniformly in matrix. In this article, the dispersing of ZrO2 and SiC nanometer particles in the preparation process of ZrO2/SiC-MoSi2 composites were investigated with multiphase suspensions mixed. SiC and ZrO2 nanoparticles were dispersed with water and the alcohol as the dispersion medium, PEG, PAA - NH 4 and PMAA - NH4 as the dispersing agent. Simultaneously the effect of the surface pretreatment on the dispersive influence of SiC nanoparticles were studied. The Zeta electric potential test and the subsidence experiment indicated that the dispersibility of SiC nanoparticles can be effectively improved after calcinated at 550℃ for two hours in air. The dispersing effect of nanoparticles using water were better that using alcohol.The dispersion of ZrO2 is PAA-NH4 , the best effect of dispersing of sic is at the dispersion medium