Abstract: Al₂O₃/5vol%W and Al₂O₃/10vol%W nanocomposite powders, with mean particle size less than 50nm, were prepared by the heterogeneous precipitation
process using Al(NO₃)₃·9H₂O and (NH₄)₂CO₃ solutions as raw materials and tungsten nanometer powders as additives in different ratios. α-Al₂O₃/W
nanocomposite was obtained by calcining Al(OH)₃/W dried gel at 1000℃ for 1h in vacuum. Adding tungsten nanometer powders can reduce the phase transformation
temperature to alpha alumina. The composite powder is simply mechanically mixed together, alumina coating is on the surfaces of nanometer tungsten powder.

Key words: nanocomposite powder, α-Al₂O₃/W, heterogeneous precipitation