铝热还原氮化法一步烧结制备AlON陶瓷研究
One step preparation of AlON ceramics by aluminothermic reduction and nitridation

以微米Al粉和纳米γ-Al？？？？2？？O？？？？3？？为原料，采用铝热还原氮化法在流动N？？？？2？？中进行了AlON陶瓷的一步反应烧结制备.结果表明，合成纯相AlON的最佳Al含量为11 wt%.在1650℃以下Al先和N？？？？2？？反应生成AlN，AlN再在1650℃以上与Al？？？？2？？O？？？？3？？通过固相反应生成AlON，并在1700℃制备了纯相的AlON，但此时块体中的AlON颗粒几乎没有出现烧结，在更高温度下才合并长大形成AlON陶瓷.煅烧温度较低时（≤1700℃），样品表面和内部的物相组成基本相同，但在高温下（≥1750℃）内部仍为纯相AlON而表层却被过度氮化出现AlN杂相.最后用热力学对该现象进行了分析.
AlON ceramics were prepared by one-step aluminothermic reduction and nitridation method using micron-sized Al and nanoscale γ-Al？？？？2？？O？？？？3？？ powders as the starting materials. The results showed the optimal Al content for single-phase AlON preparation was 11 wt%. At the temperature below 1650℃, AlN was primarily produced by direct Al nitridation. Then AlN reacted with Al？？？？2？？O？？？？3？？ forming AlON at above 1650℃. Single-phase AlON was synthesized at 1700℃, but the sintering among AlON particles was barely observed, which only occurred at higher temperature. For samples calcined at low temperature (≤1700℃), the phase compositions of both interiors and exteriors were basically the same. However, the interiors maintained pure AlON while the exteriors were over nitrided and AlN impurity appeared at high temperature (≥1750℃). Such phenomenon was analyzed with emphasis of thermodynamics