【摘要】 研究了在中位径为 0 .42 μm的碳化硼微粉中添加 1 %～ 4%碳为活化剂的烧结过程。研究了烧结坯的密度、抗弯强度、晶粒度与掺碳量、烧结温度、保温时间的关系。在一定烧结温度以上 ,少量碳的掺入明显提高了烧结活性 ,烧结坯密度明显提高 ,在本实验条件下 ,最佳掺碳量为 1 %～ 2 % ,最佳烧结温度为 2 1 60～ 2 2 0 0℃。研究了掺碳碳化硼烧结动力学 ,得出其物质迁移机制主要为晶界扩散。最后研究了其相组成 ,掺入的碳除溶解于碳化硼外 ,以游离碳形式存在 ,没有新相生成。更多还原

【Abstract】 The activated sintering processes of boron carbide with 1%～4% carbon as activator were studied. The mean size of boron carbide ultra fine powder was 0.42 μm. The relationships between the density, bending strength and grain size of the sintered compact and the quantity of additives, sintering temperature, sintering time were investigated. It was showed that the density of the sintered compact increased even with the addition of little amount of additive(carbon). The optimum amount of the additive (carbon) is 1%～2%, and the optimum sintering temperature is 2 160～2 200 ℃. The activated sintering kinetics of boron carbide with carbon as activator were also researched, the results showed that the main transport mechanism was grain boundary diffusion. Finally, the constitntion of carbon phase was studied, it was showed that the form of the added carbon after sintering was free carbon besides those dissolved in boron carbide, and no new phase was formed.更多还原