超重力燃烧合成快速制备MgAl_2O_4陶瓷的研究

Rapid Preparation of MgAl_2O_4 Ceramics by High-gravity Combustion Synthesis

采用超重力燃烧合成技术快速制备了MgAl_2O_4陶瓷,研究了铝热剂组分和超重力系数对MgAl_2O_4样品的结构和性能的影响。实验结果表明:采用(Al+CuO+Cu)铝热剂,通过超重力燃烧合成,可以获得较为致密的MgAl_2O_4陶瓷样品。与常规重力场相比,在超重力场作用下,铝热反应产生的金属熔体与陶瓷熔体分离更加彻底,表明超重力场可有效加速相分离。铝热剂中Cu稀释剂含量对产物的相组成和致密度也有明显影响,Cu稀释剂含量过高时,相分离和气孔排除不彻底。

Mg Al_2O_4 ceramics were rapidly prepared by high-gravity combustion synthesis, and the effects of thermite compositions and high-gravity coefficients on the microstructure and properties were discussed. The results show that with the thermite consisted of Al+Cu O+Cu, compact bulk Mg Al_2O_4 ceramics can be prepared by high-gravity combustion synthesis. Compared to in normal gravity, the phase separation between metal and ceramic melts can be efficiently improved in high-gravity field. However, the Cu diluents also has a remarkable effect on the phase compositions and density, and the phase separation as well as gas evacuation was not completely with excessive Cu diluents.