Production of nanometer-sized AlN powders by the exploding wire method

We have performed experiments to explore the possibility of making pure nan ometer-sized AlN powders by electrical explosion of aluminum wire in an atm osphere of nitrogen-containing gases. It is shown that raising the density of the energy injected into the metal, applying increased pressures, and a high working-gas flow rate help assure the production of AlN powders with a specific surface up to 53 m(2)/g, d(BET) = 35 nm Particle shape ranges fro m nearly spherical to rigorous-cut particles. The yield of such powder acco unts for 50 % of the total mass of powder. The powder thus produced contain s no more than I wt.% of impurities, including oxygen. (C) 1999 Acta Metall urgica Inc.