| 摘要 |
PURPOSE:To remove only components other than the basic component in a sintered body without changing the basic properties of the sintered body by heat-treating an atmospherically sintered h-BN-based ceramic body at high temp. or at high temp. in vacuum or treating the body with an acidic soln. CONSTITUTION:An atmospherically sintered h-BN-based ceramic body is heat- treated at high temp. or at high temp. in vacuum or treated with an acidic soln. The volatile component in the body is removed at >= 1500 deg.C in the case of the high-temp. heat treatment, and the volatile component is removed at >=1200 deg.C and at 0.1 Torr in the case of the high-temp. vacuum treatment. The volatile component is removed in the case of acidic soln. treatment, since the soln. of HCl, HF, HNO3 or H2SO4 is used. Only the volatile component is removed from the sintered body by this method while retaining its basic physical properties such as corrosion resistance to molten material and inorg. matter, unwettability and strength. |
