Demir, V.Thompson, D. P.2024-09-292024-09-292007978-0-87849-439-20255-5476https://doi.org/10.4028/www.scientific.net/MSF.554.107https://hdl.handle.net/20.500.14619/75335th International Symposium on Nitrides -- APR 03-05, 2006 -- Anadolu Univ, Eskisehir, TURKEYSilicon nitride samples were pressureless sintered with up to 5 w/o MgO to give densities in the range 98-99% of theoretical. After pressureless sintering, selected samples were placed in a vacuum heat treatment furnace surrounded by a carbon bed in a carbon crucible at a pressure of less than 4x10(-4) mbar, and vacuum heat treated at different temperatures and times to remove grain-boundary glass. The results showed that this was substantially achieved at 1575 degrees C for 3h and that increasing the time to 5 hours gave still further improvement. SEM images, EDX analysis and oxidation tests provided additional evidence for the removal of Mg from the samples.eninfo:eu-repo/semantics/closedAccesssilicon nitride ceramicssinteringMgOvacuum heat treatmentglass removalConference Object10.4028/www.scientific.net/MSF.554.107+107554WOS:000248530400017N/A