| 摘要 |
PURPOSE:To improve sinterability by dispersing powder based on Al2O3 and SiO2 in an acidic soln. contg. Al and Si components, forming a precipitate and carrying out calcination. CONSTITUTION:Al2O3 powder is wet-mixed with SiO2 powder in a ball mill, etc., and the resulting slurry is dried, calcined and pulverized to obtain powder based on Al2O3 and SiO2 giving the compsn. of mullite. An Si component such as colloidal SiO is dissolved in a soln. prepd. by dissolving metallic Al in hydrochloric acid to prepare an acidic soln. having 0.001-0.5mol/kg concn. (expressed in terms of mullite). The powder based on Al2O3 and SiO2 is added to the acidic soln. and well dispersed and a precipitate is formed by adjusting the soln. to pH5-9 with an aq. NH3 soln. This precipitate is separated by filtration, washed, dried and calcined at >=500 deg.C to obtain easily sinterable Al2O3.SiO2 powder. |
