ABSTRACT: Alumina(A1203)has been widely applied in great many different industrial areas. With the development of new material science and advanced manufacturing technology,the need for improving the purity fine grain size, surface activation of alumina has long been recognized to increase the mechanical properties of alumina-based composites such as ceramic materials. The alumina powders pared with conventional methods call not satisfy this high requirement. The sol-gel method is one of the most important techniques for preparing high quality nanoscale powders since it provides a high-purity, low temperature synthesis and especially a precise composition control. On the other hand, the sol-gel method can be used to coat other materials to improve their surface performance. It can overcome many of the disadvantages of conventional techniques because it is simple, less expensive and allows coating of complex geometry. The nanoscale alumina(A1203)powders were prepared from the raw materials of aluminium-iso-propoxide (Al(C3H7O)3) with the sol-gel technology. The transformation process from the gelata to the alpha alumina powders has been investigated by means of X-ray diffraction analysis and dlfferential themlal analysis. All the factors that affect the performance of the alpha alumina powders were also discussed in detail. It was found that the gel could be completelv transformed into α-A1203, and sintered to relatively high density at 1200, as the activity of colloidal particles was very high. The prepared nanoscale alumina was polycrystalline and isotropic and no weak phase was found in the alumina powders. It was verified that the sol-gel method is a promising technique for preparing nanoscale ceramic powders.

KEYWORDS: Sol-gel technology   Aluminium-iso-propoxide     α-alumina      Nanoscale alumina