| 摘要 |
[PROBLEMS] To provide a process for recovering, by a simple means, the light transmission properties of an aluminum nitride sintered body which light transmission properties have been lowered by processing after sintering. [MEANS FOR SOLVING PROBLEMS] A process for producing an aluminum nitride sintered body having improved light transmission properties of the present invention comprises subjecting an ordinary aluminum nitride sintered body to thermal treatment in an inert atmosphere at a temperature of from 1300 to 1400°C for at least 1 hr. A cover for light sources of the present invention comprises a hollow aluminum nitride sintered body having a light transmittance in the visible light region of at least 87%, which body is obtainable by thermally treating a hollow aluminum nitride sintered body in an inert atmosphere at a temperature of 1300 to 1400°C for at least 1 hr. |
