| 摘要 |
PURPOSE:To obtain AlN powder having low cation impurity content, high tap density and excellent moldability by heating a mixture of alumina and carbon in an N2-containing atmosphere, crushing the obtained reaction product and removing excess carbon by burning. CONSTITUTION:The AlN powder contains <=2.0wt.% of oxygen, <=20ppm of iron, <=100ppm of Si and <=20ppm of Ti and has a tap density of >=1.0g/cm<3>. The AlN powder can be produced by the following procedures. A mixture of alumina powder and carbon powder is made to react in an N2-containing atmosphere at about 1500-1700 deg.C for about 2-10hr by a reducing nitriding process. The reaction product is usually a mixture of AlN powder and excess carbon powder and gives AlN powder containing small amount of agglomerated particles and having low tap density even by burning and removing the excess carbon. Accordingly, the above reaction product is crushed and heated in air at about 600-750 deg.C to effect the combustion and removal of the excess carbon. |
