液相烧结氧化铝陶瓷及其烧结动力学分析

研究了CuO TiO2复相添加剂对Al2O3陶瓷烧结性能、显微结构的影响以及添加剂形成液相时Al2O3陶瓷的烧结动力学.结果显示:添加剂的加入明显地促进了Al2O3陶瓷的烧结致密度.添加剂含量对致密有明显影响,含量越高,烧结速率越快.当添加剂(CuO TiO2)为2%(质量分数),CuO/TiO2质量比为1/2时,Al2O3样品致密度最高.添加剂的存在使Al2O3晶粒发生较快生长,晶粒形貌为等轴状.通过等温烧结动力学,确定掺杂Al2O3陶瓷烧结激活能为25.2kJ/mol,表明可能是氧离子和铝离子在液相中的扩散作用控制了烧结过程.

LIQUID-PHASE-SINTERING OF ALUMINA CERAMICS AND SINTERING KINETIC ANALYSIS

The effect of the addition of CuO and TiO2 on the sintering and microstructure of alumina ceramics was investigated. The sintering kinetics of alumina was also studied in the presence of liquid phase formed by CuO and TiO2. It was found that the sintering densification of alumina ceramic is greatly enhanced by the addition of CuO and TiO2. The sintering rate of alumina increases with the increase of the additive content. The density of alumina ceramic reaches a maximum when the content of additives CuO+TiO2 is 2% (in mass) and the mass ratio of CuO and TiO2 is 1/2. The grain growth of alumina is promoted by the additives, and the shape of the grains is equiaxed crystal. The sintering activation energy of alumina ceramics is 25.2 kJ/mol by determining according to isotrermal sintering kinetics. The results indicate that the sintering process is possibly controlled by the diffusion of Al3+ and O2- in the liquid phase.