Low-Temperature Synthesis of [alpha]-Al.sub.2O.sub.3

The paper examines the low-temperature [gamma]-Al.sub.2O.sub.3 [right arrow] [alpha]-Al.sub.2O.sub.3 phase transformation in [gamma]-Al.sub.2O.sub.3 powder for chromatography with AlF.sub.3 mineralizer. Changes in the AlF.sub.3 amount (2-3 wt.%) and isothermal holding time at 850°C allow variation in the powder phase composition, specific surface area (from 85.5 to 0.2 m.sup.2/g), and morphology (from spheroids to lamellas). The experimental results serve as a basis for designing precipitation-strengthened composites consisting of a ZrO.sub.2 solidsolution matrix and a strengthening [alpha]-Al.sub.2O.sub.3 phase.