Process for making a shaped object from nitride of elements selected from groups III, IV, V or VI of the Periodic Table, in particular from silicon nitride

摘要

The porous shaped object is placed into a hot-isostatic press. In the second sintering phase, the shaped object is exposed for at least 30 minutes to a nitrogen atmosphere pressure of at least 100 bar and a temperature of at least 1200 DEG C. The second sintering phase is carried out without addition of sinter aids and without an extraneous gas-tight envelope. This treatment gives a solid shaped object whose density is at least 2.0 g/cm<3> and whose HVO.05 hardness is in the range from 13,000 to 15,000 N/mm<2>. Nitriding throughout the entire shaped object is achieved.