Demir, V.Thompson, D.P.2024-09-292024-09-2920070878494391978-087849439-20255-5476https://doi.org/10.4028/0-87849-439-1.107https://hdl.handle.net/20.500.14619/8914Scientific and Technological Research Council of Turkey5th International Symposium on Nitrides -- 3 April 2006 through 5 April 2006 -- Eskisehir -- 71251Silicon 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 4×10 -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°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/closedAccessGlass removalMgOSilicon nitride ceramicsSinteringVacuum heat treatmentConference Object10.4028/0-87849-439-1.1072-s2.0-38349105376112Q4107554