摘要
通过高温热膨胀仪对微米级α-Al2O3坯体进行两种升温速率(2℃/min和5℃/min)的恒速无压烧结,利用阿基米德法测量烧结体的相对密度,利用扫描电镜观察样品经不同烧结路径烧结后的显微结构;以Hansen全期烧结模型为基础,根据两种升温速率下得到的烧结曲线,建立了微米级α-Al2O3(平均粒径为2.5μm)主烧结曲线;利用主烧结曲线得到的相对密度和阿基米德法测得的烧结体(经过不同烧结制度)相对密度一致,说明主烧结曲线对烧结路径不敏感,烧结体的相对密度仅是时间和温度的函数,从而证明了所建主烧结曲线的有效性。烧结体的显微结构与烧结体密度密切相关,因此主烧结曲线可以用来预测和控制烧结体的显微结构,进而实现对氧化铝陶瓷性能的预测和控制。
The master sintering curve （MSC） of 2. 5μm α-Al2O3 was constructed using constant heating-rate dilatometry data based on the combined-stage sintering model. The present research was taken to predict and control microstructure evolution with densification of α-Al2O3 ceramics during pressureless sintering. Densification ofα-Al2O3 was continuously recorded during sintering at the heating rate of 2 and 5℃/min. The density continuously determined by dilatometer agreed well with the densities determined by Archimedes method with different heating history. The results show that the master sintering curve, in which the sintered density is a unique function of the integral of a temperature function over time, is insensitive to the heating path. Quantitative image analysis （Scanning Electron Microscopy, SEM in brief） was used to characterize sintered microstrueture as a function of the time-temperature sintering conditions, and to verify the link between sintered density and microstructure. The results demonstrate how MSC theory can be applied to design a reproducible process to fabricate controlled density and microstructure ceramics.
出处
《材料科学与工程学报》
CAS
CSCD
北大核心
2008年第6期874-877,共4页
Journal of Materials Science and Engineering
基金
青岛市自然科学基金资助项目(05-1-JC-89)
