中文摘要：

以氧化铝粉体为原料，通过改变固含量、分散剂加入量调节浆料流变性能，采用离心式喷雾干燥工艺制备出氧化铝微珠坯体。研究了固含量、分散剂加入量对氧化铝浆料流变性以及微珠坯体形貌的影响，分析了“苹果型”缺陷坯体的形成过程。结果表明：随着浆料固含量的增加，规则球形坯体数量呈现迅速增多然后缓慢减少的趋势，随着分散剂加入量的增加，规则球形坯体的数量先增多然后逐渐减少，当浆料固含量为40％（体积分数）、分散剂加入量为0．5（质量分数）％时，球形坯体数量的比例最高为92．9％；“苹果型”缺陷坯体的形成受浆料固含量的影响显著，固含量为20％时，颗粒间距为0．549μm，坯体中规则球形坯体仅有14．6％，大部分是“苹果球”坯体，固含量为40％时，颗粒间距为0．157μm，球形坯体比例为92．9％，仅形成少量的“苹果球”坯体，因此，固含量越低，颗粒间距越大，坯体形成过程中空洞出现的越多，导致最后形成大量的“苹果球”坯体。采用二次烧结的方法对Al2O3坯体进行烧成，经1700℃烧成的Al2O3微珠抗压强度达到了105．6MPa。

英文摘要：

Alumina microspheres were prepared by centrifugal spray drying using alumina powder as a starting material. The influences of solid loading and dispersant addition amount in alumina slurry on the performance of the green body were investigated. The formation mechanism of apple-shaped green body was also discussed. The number of sphere-shaped green body first increases, and then decreases with the increase of solid loading. When the dispersant addition amount increases, the number of sphere-shaped green body first increases and then decreases. An aqueous slurry with 40% （in volume fraction） of alumina and 0.5% （in mass fraction） of dispersant addition amount can be transformed into a green body with microspheres, obtaining a high pellet yield of 92.9%. The solid loading of alumina slurry has a dominant effect on the apple-shaped green body. When solid loading is 20%, the distance between particles is 0.549 μm, the proportion of spherical green body is 14.6%, including most apple-shaped green bodies. When solid loading is 40%, the distance between particles is 0.157 μm, and the proportion of spherical green body is 92.9%. A lower solid loading results in a greater space, causing the more holes in the green bodies. As a result, massive apple-shaped green bodies appear. The two-step sintering process is adopted to prepare alumina microspheres, and the compressive strength of microspheres sintered at 1 700 ℃ can reach 105.6 MPa.