氧化铝α相变及其相变控制的研究

Mechanism and Control of α-Phase Transformation of Alumina

综述了氧化铝相变的机制、α相变温度控制的方法及其相关的机理。通过对氧化铝前驱体的球磨 ,在前驱体中引入α氧化铝籽晶 ,或者加入TiO2 ,MgO ,NH4 NO3等矿化剂可以降低氧化铝前驱体的α相变温度 ,从而得到粒径细小、无硬团聚的氧化铝粉体。相反 ,在某些具体应用时需要提高氧化铝α相变温度 ,提高氧化铝的热稳定性能 ,使用氧化铝热稳定添加剂被认为是一种很有效的方式。

The mechanism of alumina phase transformation, and the means to control the α phase transformation temperature and concerned mechanism were reviewed. Milling process, α-Al_2O_3 seeding, and some additives such as TiO_2, MgO, NH_4NO_3, etc, were usually adopted to decrease the α-phase transformation temperature, leading to producing ultrafined and agglomeration-free alumina powder. On the contrary, during some concrete application processes, it′s necessary to enhance the α-phase transformation temperature, so as to improve the thermal stability of alumina powder. And the doping with stabilizing additives is always considered to be an effective attempt.