Al_2O_3透明陶瓷的显微组织和性能

MICROSTRUCTURES AND PROPERTIES OF Al_20_3 TRANSPARENT CERAMICS

采用高纯Al2O3粉末(>99.99%)为原料,1850℃氢气气氛中烧结了氧化铝透明陶瓷。研究了添加剂MgO、预烧温度、保温时间对Al2O3透明陶瓷显微结构和光学性能的影响。实验结果表明,掺杂MgO含量为0.05wt%时能够抑制晶粒生长,改善烧结性能,但添加剂含量较多,透光率下降;随着预烧温度从700℃到1150℃,样品透光率增加,1150℃预烧的氧化铝在同样烧成温度下具有好的透光性;保温时间4h,晶粒充分长大,晶界清晰,大于8h,晶粒产生异常生长。

Optical transparent polyerystaUine Al2O3 ceramics were sintered at 1850 ℃ in H2 atmosphere. MgO additive, pre-sintering temperature and holding time were investigated. The results indicated that 0.05wt% of MgO could inhitite the grain growth and improve sintering performance, while porosity increased and transmittance decreased with the continuing increase of MgO content ;transmittance increased when pre-sintering temperatures elevated from 770℃ to 110℃ and the optimum transmittance was obtained at 1150℃ grains fully developed and grain boundaries were clear when holding time was 4h, but grains appeared abnormal growth when holding time exceeded 8h.