Preparation of α-Al_2O_3/W Nanocomposite Powder

Al2O3/5vol%W and Al2O3/10vol%W nanocomposite powders, with mean particle size less than 50nm, were prepared by the heterogeneous precipitation process using A1(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 A1(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.