| 摘要 |
In preparing a sintered silicon nitride body by hot isostatic pressing, a composition comprising Si3N4 and a sintering aid is molded to form a green molded body, the surface of the green molded body is coated with a composition comprising Si3N4 and a sintering aid and having a sintering temperature lower than that of the composition of the green molded body, the coated green molded body is preliminarily sintered so that only the coating layer is densified, and the preliminarily sintered molded body is subjected to hot isostatic pressing. The obtained sintered body has a surface compression stress, and by this surface compression stress, not only the strength at room temperature but also the strength at high temperatures is improved. |
