透辉石增韧补强氧化铝基陶瓷材料烧结动力学和烧结机制

Sintering Kinetics and Mechanisms of Alumina Matrix Ceramic Materials Toughened by Diopside

研究了透辉石增韧补强A l2O3基陶瓷材料的无压烧结致密化过程,根据压坏烧结时烧结温度和保温时间对线收缩率的影响,计算了复合材料液相烧结的表观激活能Q,得出其致密化机理为扩散机制控制。建立了透辉石增韧补强A l2O3基陶瓷材料的烧结动力学方程,并由特征指数n值对比研究了它们的烧结致密化机制。纯A l2O3陶瓷材料烧结过程中的物质迁移机制由体扩散控制;透辉石增韧补强A l2O3基陶瓷材料烧结过程中的物质迁移机制既有体扩散,也有晶界扩散。

Sintering densification process of alumina matrix ceramic materials toughened by diopside were studied in this paper. The apparent activated energy was calculated according to the influence of sintering temperature and holding time on linear shrinkage rate. Results show that the densification of alumina matrix ceramic materials toughened by diopside may be controlled by diffusion. The sintering kinetic equations were deduced and the sintering mechanisms were analyzed by comparing the characteristic exponent. It is indicated that the main sintering mechanism of pure alumina may be volume diffusion, and that of alumina matrix ceramic materials toughened by diopside may be volume diffusion and grain boundary diffusion.