The purpose of this study was to explore the preparation method of nanometer powders of dental alumina ceram2 ics. Methods : The effects of concentration of inorganic precursors , pH value , calcination temperature and ageing time on the syn2 thesizing process , phase composition and microstructure of the materials were studied. Aluminium nitrate with concentrations of 0103 molPL , 0105 molPL , 011 molPL and 012 molPL were used as inorganic precursors to prepare alumina powders via sol-gel method. Ammonia water was added into the solutions to adjust the pH values to 5 , 9 and 11. The dried gel was then calcined un2 der different temperatures , from 950 ℃to 1200 ℃. The prepared alumina powders were studied by using X- ray diffraction (XRD) , and scanning electron microscope (SEM) . Results : The alumina powder which was prepared with 0. 1 molPL aluminium nitrate , pH 9 , and calcined at 1200 ℃for 10 min showed good physical characteristics. The diameter of final powder was about 70 nm. Conclusion : With the proper preparation condition , weakly agglomerated powders of alumina in nanometer particle size could be obtained.
