碳化硅复合多孔陶瓷支撑体的制备与性能研究

发布时间：2018-02-27 18:06

  本文关键词： 碳化硅 原位反应结合 抗弯强度 多孔陶瓷　出处：《海南大学》2015年硕士论文　论文类型：学位论文

【摘要】：高温过滤除尘系统是整体煤气化联合循环发电机组的关键子系统,对电站的稳定运行和发电效率有重要影响。非对称过滤结构的多孔陶瓷管是除尘系统的核心部件,它由起过滤除尘作用的过滤膜和承载过滤膜的支撑体构成。支撑体的机械强度和孔隙结构对除尘系统的使用寿命、过滤效率和过滤精度有决定性的影响。 本文以制备高强度、高孔隙率的碳化硅复合多孔陶瓷支撑体为研究目标。系统研究了陶瓷粘结剂生料成分及含量、坯体成型压力、烧结温度、烧结氛围、成孔方式对支撑体微观结构、抗弯强度和气孔率的影响,深入研究了气孔率与支撑体抗弯强度的关系,制备出了高强度高气孔率的多孔陶瓷样品。碳化硅平均粒径23μ m,铝矾土添加量为30wt%,造孔剂石墨添加量1Owt%,坯体成型压力30MPa,1400℃空气中烧结,制备出了抗弯强度41.OMPa,气孔率为44.9%的碳化硅/莫来石复合多孔陶瓷。 为了降低主要粘结相莫来石的生长温度,改善其结晶形貌,先将碳化硅粉体与白炭黑混合并加入pvb造粒,在非氧化性烧结氛围下,模拟原位反应结合技术制备了碳化硅复合多孔陶瓷支撑体,并系统研究了三水氟化铝添加量和烧结温度对其微观形貌和性能的影响。当碳化硅(6μm)含量39.7wt%、白炭黑含量17.0wt%、纳米氧化铝含量43.3wt%的混合料,外加4wt%的三水氟化铝,坯体成型压力36MPa,颗粒堆垛成孔,烧结温度1300℃时,制备出了抗弯强度31.1MPa,显气孔率为42.8%的碳化硅多孔复合陶瓷支撑体,其物相组成主要是碳化硅、莫来石、刚玉和少量方石英。
[Abstract]:The high temperature filtration and dust removal system is the key subsystem of the integrated coal gasification combined cycle generator unit, which has an important effect on the stable operation and power generation efficiency of the power station. The porous ceramic tube with asymmetric filter structure is the core component of the dust removal system. It is made up of filter membrane and supporting body carrying filter membrane. The mechanical strength and pore structure of the support have a decisive effect on the service life, filtration efficiency and filtration precision of the dust removal system. In this paper, the preparation of silicon carbide composite porous ceramic support with high strength and high porosity was studied. The composition and content of ceramic binder, the forming pressure, sintering temperature and sintering atmosphere of ceramic binder were studied systematically. The effect of pore forming mode on the microstructure, bending strength and porosity of the support was studied. The relationship between the porosity and the bending strength of the support was studied. The porous ceramic samples with high strength and high porosity were prepared. The average particle size of silicon carbide was 23 渭 m, the amount of bauxite was 30 wts, the amount of graphite was 1 Owt, and the molding pressure of the billet was 30 MPA / 1 400 鈩，

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