高纯度氧化铝粉体颗粒细化对烧结致密化及透光性能的影响

EFFECTS OF HIGH PURITY ALUMINA POWDER MODIFICATION ON THE SINTERING DENSIFICATION AND TRANSLUCENT PROPERTIES OF ALUMINA CERAMICS

以法国Baikowski公司高纯度氧化铝粉体为参照,选取大连瑞尔精细陶瓷有限公司产超高纯度氧化铝粉体为研究对象。采用研磨处理,以改善国产氧化铝粉体的形貌、粒径及其分布。分别采用硅钼电炉中常压烧结和真空气氛下在1850℃烧结2种不同的烧结方式评价了研磨后粉体的烧结性能和用于制备半透明氧化铝陶瓷的可行性。结果表明:经过研磨改性处理后,粉体的粒径分布和比表面积接近于法国粉体;在1600℃常压烧结得到的氧化铝陶瓷达到理论密度的97%,具有均一的晶粒尺寸(～5μm)。添加MgO为烧结助剂,在真空下烧结得到了半透明氧化铝陶瓷,在波长为200～1100nm范围直线透过率最大值达到16%。

According to the properties of the commercial alumina powder from Baikowski Co. Ltd. in France,the alumina powder with ultra-high purity prepared by Dalian Rall Fine Ceramic Co.,Ltd. was milled in order to modify the particle and grain morpholog,size and distribution in the sintered alumina ceramics. The sintering properties of both alumina powder were evaluated by two sintering methods,pressureless sintering in muffle furnace at different temperatures and sintering in vacuum tungsten filament furnace at 1 850 ℃. The results show that the particle size and distribution of the domestic powder after milled are very close to those of the alumina powder from Baikowski Co. Ltd. Sintered at 1 600 ℃ without sintering aid,the alumina ceramics prepared with the domestic powder have homogenous crystal grain size with approximately 5 μm in diameter,and the relative density is 97%. Doped with MgO,a translucent alumina ce-ramic was successfully sintered in vacuum atmosphere and its in-line transmittance reached the highest value of 16% from 200 to 1 100 nm.