采用模板法制备毫米级半透明Al2O3空心球

Preparation of Translucent Al_2O_3 Hollow Spheres in Millimeter-scale via a Template Method

以自制毫米级聚苯乙烯(PS)球为模板,采用物理包覆和真空烧结方法制备Al2O3半透明空心球。用离心加压物理包覆法制备PS–Al2O3复合球壳,经3步煅烧法制备出毫米级半透明氧化铝空心球。制备过程为:第1步以1℃/min的升温速率在320℃保温2 h和900℃保温2 h,去除模板得到白色氧化铝空心球素坯;第2步在1 300℃保温2 h,去除残余模板和大部分气孔,对氧化铝空心球壳预烧结;第3步在1 800℃真空条件下烧结,得到半透明氧化铝空心球,其球壳厚度约为150μm,具有较高的致密度,可用作惯性约束核聚变靶丸材料。

The translucent A1203 hollow spherical ceramics were prepared with the polystyrene sphere （PS） template via mechanical coating and sintering in vacuum. In the mechanical coating process, the PS-Al2O3 core-shell structures were obtained by means of centrifugal force. The translucent A1203 hollow spheres in millimeter-scale were prepared as following stages：1） removal of the template to obtain alumina hollow sphere by calcination at 320℃ Cfor 2 h and 900℃ for 2 h with a heating rate of 1℃ /min; 2） sintering of alumina hollow spheres to remove the template completely and most of the pores by calcination at 1 300℃ for 2 h; and 3） sintering of alumina hollow spheres at 1 800℃ in vacuum. The hollow spherical ceramics calcined show better morphology and mechanical property. The thickness of alumina shell is 150μm, which is appropriate for the promising application of inertial confined fusion.