Synthesis of Alumina Powders by Mechanical Activation

Abstract

Alumina is utilized in many areas of modern industry because of its unique mechanical, electrical and optical properties. Various methods are been employed for produce alumina for different end uses. The preparation of fine and sintering-reactive alumina powders is probably one of the most important steps for production alumina ceramics with controlled microstructure. In this work, it was studied the production of alumina powders by “Pechini” method associated to highenergy milling. For this, it was prepared the resin by Pechini method, using aluminum nitrate nonahydrate. This resin was calcined at 500oC. Then, the calcined powders were submitted a high energy milling for different times. The powders mechanically activated were characterized by x ray diffraction, FT-IR and scanning electronic microscopic. After milling, the powders were calcined at 900oC. The results showed that the alumina phase transitions and powders characteristics were modified when the step of activation mechanical was introduced.