高致密氧化镁陶瓷的凝胶注模成型

探讨了高致密氧化镁陶瓷水基凝胶注模成型工艺,研究了预烧处理温度对原料的水化活性、粒度及比表面积的影响;同时研究了预烧处理温度、分散剂及固含量等对MgO陶瓷浆料流变学性能的影响。通过DSC-60A热分析仪对MgO陶瓷素坯进行热分析,制定了合适的烧结制度;用SSX-550观察了烧结体的微观形貌。结果表明,MgO粉体随着预烧处理温度的升高,水化活性降低,粒度增大,比表面积降低。在1 350℃处理后的MgO粉活性最低,当分散剂的加入量为3%时,可制备出固含量为54%、黏度低于200mPa.s的流动性良好的稳定浆料。MgO烧结体的密度可达到理论密度的98.32%,且烧结体宏观无缺陷,微观结构均匀致密。

Preparation of high density magnesia ceramic by gelcasting

The effects of the pre-burn treatment on the hydration activity of raw materials,grain size and specific surface area and the effects of pre-burning temperature,dispersion agents and solid content on the rheological properties of MgO ceramic slurry were studied.Thermal analysis of MgO ceramic green body was studied by DSC-60A thermal analyzer and a suitable sintering schedule was accordingly worked out.The morphology of the sintered bodies were observed by SSX-550.With the increased pre-burn processing temperature the hydration activity and the specific surface area of MgO material powder was decreased but the particle size was increased.The lowest hydration activity of MgO powder were obtained when treated at 1 350 ℃.The MgO slurry with 54% solid loading and 200 mPa·s were prepared when 3% dispersant was added.The density of sintered MgO ceramics is 98.32% of theoretical density,which was macro-defect-free and homogeneous and compact microstructure.