| 摘要 |
PURPOSE:To efficiently produce the title high-purity AlN powder having high thermal conductivity, by nitriding a mixture of Al powder, a fluorine-contg. ammonium compd., and AlN powder, introducing a reducing gas, and then keeping the atmosphere at a vacuum. CONSTITUTION:The mixture of metallic powder, a fluorine-contg. ammonium compd. (e.g., NH4F), and AlN powder is heated at 300-550 deg.C for several hours in a nitriding gas atmosphere to uniformly nitride the surface of the Al powder. The mixture is then heated for 1-5h4 at a temp. higher than the m.p. Al (900-1,300 deg.C) to completely nitride the Al. The reducing gas such as gaseous decomposed ammonia and gaseous H2 is introduced into the atmosphere, and allowed to stand for a specified time to carry out deoxidation. The gas is then discharged, the atmosphere is kept at 10<-3>Torr, the atmosphere is heated at 1,300-170 deg.C to remove the metal element, and the high-purity AlN powder contg. <=0.6wt.% total metal elements and having about 0.75mum particle diameter is obtained.
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