烧结助剂Y2O3和Pr6O11对Al2O3陶瓷相对密度和热导率的影响

采用高分子网络法制备混合纳米粉体,研究稀土氧化物Y2O3和Pr6O11加入量对Al2O3陶瓷相对密度和热导率的影响。采用阿基米德方法测定样品的体积密度,利用激光脉冲法测量试样的热扩散率并计算得出热导率。结果表明:两种添加剂都可以降低Al2O3陶瓷的烧结温度,提高Al2O3陶瓷的热导率,其中Y2O3的促进作用较强;当保温时间相同、烧结温度为1 500~1 650℃时,Al2O3陶瓷的相对密度和热导率都随烧结温度的升高而增大;当烧结温度相同、保温时间为30~120 min时,Al2O3陶瓷的相对密度和热导率也随保温时间的延长而增大。

Effects of sintering aids Y2O3 and Pr6O11 on relative density and thermal conductivity of Al2O3 ceramics

The effects of the amounts of Y2O3 and Pr6O11 on the relative density and thermal conductivity of the Al2O3 ceramics were investigated by preparing mixed nanometer powders through polymer network method.The bulk density of the Al2O3 ceramics was measured by the Archimedes method.The thermal diffusivity was measured by the laser pulse method,and the thermal conductivity was calculated.The results show that both sintering aids in the alumina powders can decrease the sintering temperature and improve the thermal conductivity,and the role of Y2O3 is more effective.When the holding time is the same and the sintering temperature is 1 500-1 650 ℃,the relative density and the thermal conductivity of Al2O3 ceramics increase with the increase of the sintering temperature.When the sintering temperature is the same and the holding time is 30-120 min,the relative density and thermal conductivity of Al2O3 ceramics also increase with the increase of the holding time.The causes affecting the thermal conductivity of Al2O3 ceramics are explained according to the microstructure and the theory of heat transfer by phonon.