Process for production of sintered silicon nitride made article.

摘要

There is provided a process for the production of a sintered article which comprises steps of shaping a raw material powder comprising silicon nitride, thermally treating a shaped article in a non-oxidizing atmosphere at a temperature of 1300 to 1650 DEG C for at least 2 hours to form beta -silicon nitride of not less than 85 % calculated from X-ray diffraction patterns and to increase a relative density of the article to not less than 80 %, preferably to 80 to 85 %, and sintering the thermally treated article at a temperature of 1700 to 2000 DEG C.