环境温度和湿度对96-Al_2O_3陶瓷电阻率的影响

采用无压烧结技术,以0.25wt%CaO、1wt%MgO、2.75wt%SiO_2为添加剂,在1500℃、1550℃、1600℃下烧结制备了Al_2O_3陶瓷,分别在150~400℃温度范围内和40%~100%的相对湿度环境下,对Al_2O_3陶瓷的直流电阻率进行检测。样品的相组成和显微结构通过X-ray衍射分析(XRD)和扫描电子显微镜(SEM)表征。结果表明,环境温度由150℃上升到400℃,样品的直流电阻率降低了约2~2.5个数量级;环境相对湿度从40%上升到100%,样品的直流电阻下降了约3~4个数量级。在相同测试条件下,1500℃烧结的Al_2O_3陶瓷样品由于小的晶粒尺寸和高的孔隙率,从而导致其具有更高的电阻率。

Influence of Temperature and Humidity on Electrical Resistivity of 96-Al2O3 Ceramics

Al2O3 ceramics were pressureless sintered at 1500 ℃, 1550 ℃ and 1600 ℃ with 0.25wt% CaO, 1wt% MgO and 2.75wt% SiO2 as additives.The DC electrical resistivity of Al2O3 ceramics were investigated in the range of 150-400 ℃ and the relative humidity range of 40%-100% respectively.The phase composition and microstructure of Al2O3 samples were characterized by XRD and SEM.The results show that the temperature increases from 150 ℃ to 400 ℃, the DC resistivity of the samples decreases by about 2 to 2.5 orders of magnitude.The relative humidity increases from 40% to 100%, the DC resistivity of the samples decrease by about 3 to 4 orders of magnitude.At the same testing condition, the higher DC resistivity of Al2O3 samples sintered at 1500 ℃ is caused by the microstructure with smaller grain and higher porosity.