| 摘要 |
PURPOSE:To absorb foreign materials present in grain boundaries of AlN grains on a heat-resistant cellular substance and obtain a calcined AlN compact having a homogeneous color tone and structure under ordinary pressure at a low cost by bringing the above-mentioned cellular substance into contact with the outside surface of a compact containing AlN powder and a calcining assistant and calcining the compact. CONSTITUTION:A raw material containing AlN powder and a calcining assistant consisting of Y2O3, etc., is formed into a green compact. A heat-resistant cellular substance is then brought into close contact with the outside surface of the above-mentioned green compact to nip and hold both. The aforementioned green compact in this state is then calcined to absorb produced foreign materials in a molten state on the cellular substance. As a result, local gray stains or streaky patterns are prevented from occurring and a calcined AlN compact of homogeneous color tone can be surely obtained at a low cost under ordinary pressure without using a hot-pressing method. |
