快速升温、高温烧结陶瓷粉体的结构演化及致密化机理研究

Today fast-efficient sintering becomes an important direction of the ceramic technology and science due to its energy saving character and the increasingly crisis of the traditional energy. While extra current, electric/magnetic drives were specially focused to promote and shorten the sintering densification by enhancing the mass diffusion, the temperature related thermal drives always were neglected in past decades. Recently, several researches indicated the ultra thermal drive（high heating rate e.g. >100℃/sec）might be the key point of fast-efficient sintering though dispute still existed in the densification mechanism. To unclose the truth, pressless-solid sintering of several typical ceramics at high heating rate is suggested in this project. Their densification behaviors and microstructure evolution at the heating rate of ~500℃/sec will be investigated to unclose the mechanism of fast densification through the mass migration, combining with the help of numerical simulation. It is believed helpful to advance the fast-efficient sintering technology.

快速、高效的固相烧结方法是陶瓷材料制备技术发展的重要方向，它对于传统能源日益枯竭的今天具有重要的现实意义。在过去的几十年里，我们致力于采用外加电流、电/磁场等促进物质扩散的手段来加快烧结致密化进程、提高能源利用效率，而常常忽略温度相关的热驱动力。尽管在致密化机理上还存在着争议，但近来一些研究显示极端的热驱动力（快速升温, >100℃/sec）可能才是快速、高效烧结方法的关键工艺因素。为此, 在前期快速烧结技术创新和应用研究的基础上，针对研究中发现的新现象项目组提出对几种典型陶瓷在快速升温下的高温无压固相烧结进行研究，通过对典型陶瓷在不同烧结工艺条件下的微观结构演化和致密化动力学特性的表征与分析提炼在快速升温、高温烧结过程中的陶瓷物质传输机制，并结合数值模拟方法，揭示高温、快速固相烧结过程的致密化机理，为快速致密化的关键工艺因素确定提供支撑，从而促进新型快速、高效烧结技术的发展。

项目研究揭示了快速升温、高温烧结致密化过程的物理本质,研究结果显示：外加电场对于快速致密化的贡献并不明显，较快的升速度是当前陶瓷固相快速烧结技术的关键工艺因素；快速升温会导致细小的颗粒在未长大时就达到较高的温度，从而极大地激活了颗粒的移动特性。上述研究发现为烧结致密提供了新的理论途径，这个新的理论发现提炼出了快速烧结致密化的关键工艺因素，为新技术的发展提供支撑。