【作者】 王春华；

【导师】 岳新艳；

【作者基本信息】 东北大学 ， 材料学， 2011， 硕士

【摘要】 TiC-TiB2复合陶瓷材料是一种非常具有前景的高温结构陶瓷材料,在特殊电极、切削刀具、耐磨零部件以及其他特殊行业具有广泛的应用领域。一般制备TiC-TiB2复合陶瓷材料的方法有SHS和热压烧结法。但是SHS法的反应过程很难控制,热压烧结法的成本太高。这两种方法都制约了TiC-TiB2复合陶瓷材料的工业开发。无压烧结法具有烧结过程简单、能耗低等优点,能够降低材料的生产成本,因此在工业生产中具有广泛的应用市场。本文首次探索了TiC-TiB2复合陶瓷材料的无压烧结工艺,研究结果对该材料的生产和应用将具有重要的参考价值和指导意义。本文采用两种方法制备TiC-TiB2复合陶瓷材料：一种是先利用廉价的富钛原矿和硼酐原位合成TiC-TiB2复合粉体,然后无压烧结TiC-TiB2复合陶瓷材料；另一种是利用TiO2、B4C、C和TiC直接原位合成TiC-TiB2复合陶瓷材料。论文详细研究了材料的烧结工艺和烧结助剂对材料致密化、组织和性能的影响。实验结果表明：利用富钛原矿和硼酐制备TiC-TiB2复合粉体的最佳合成工艺为1450℃×30min,硼酐的最佳含量为按化学反应方程式计量的120%。利用合成复合粉体无压烧结制备复合陶瓷材料的最佳烧结温度为2100℃×90min,烧结助剂Y203的最佳含量为6%,此时复合陶瓷材料的抗弯强度和断裂韧性分别为151.4MPa和2.52MPa.m1/2。利用TiO2、B4C、C和TiC直接原位合成TiC-TiB2复合陶瓷材料的最佳合成工艺为：1400℃×30min+2000℃×90min,烧结助剂Y203的最佳含量为12%,此时复合陶瓷材料的硬度、抗弯强度和断裂韧性分别为19.98GPa、270MPa和3.54MPa·m1/2。更多还原

【Abstract】 TiC-TiB2ceramics composite has been widely used in various fields, such as special electrode, cutting tool, wear-resisting parts, which is one of the most suitable structural ceramics for high temperature applications. TiC-TiB2composite is usually synthesized by SHS and hot pressing method so far. However, it is difficult to control the reaction process for SHS and is costly for the latter method to prepare TiC-TiB2ceramics, which both restrict the development of such material. Due to characteristics of simple process and low-cost energy of pressureless sintering method, it could significantly reduce production cost of material and support widely applications in the future market. In order to reduce the production cost of materials, this study was focused on preparation of TiC-TiB2composite by pressureless sintering, which is very significant for the applications and development of TiC-TiB2ceramics composite.This study used two kinds of methods to prepare TiC-TiB2ceramics composite. One is using TiC-TiB2powders resulted from cheap titanium-rich undressed ore and boron anhydride to prepare TiC-TiB2ceramics material. The other method is using in-situ synthesized TiB2(from TiO2、B4C and C raw powders) and purchasing TiC powder to prepare TiC-TiB2ceramics composite. The sintering process and the effect of sintering aid on the density, microstructure and properties of TiC-TiB2composite were investigated in detail.The experimental results were shown as follows. For the TiC-TiB2powder preparation the best sintering process was to sinter at1450℃holding for30minutes. Corresponding to the reaction equation, the optimum ratio of raw materials was120%boron anhydride. When using homemade TiC-TiB2powders as raw material, the optimum sintering process of TiC-TiB2composite was2100℃holding for90min. When Y2O3content was6%, the TiC-TiB2ceramics material showed the optimum properties. The bending strength and fracture toughness of that were151.4MPa and3.02MPa-m1/2, respectively. On the other hand, using in-situ TiB2(from TiO2、B4C and C) and purchasing TiC powders as raw materials to prepare TiC-TiB2composite, the best sintering process was1400℃×30min+2000℃×90min. When the content of Y2O3was12%, the material showed the optimum properties. The hardness, bending strength and fracture toughness of that were19.98GPa,270MPa and3.54MPa·m1/2, respectively.更多还原